The first time you see a horse wearing sunglasses you will probably do a double take. They’re certainly not commonplace, but we’re seeing them in use more frequently and they’re not just a quirky fashion statement.

Horses wear sunglasses (often called equine goggles or visors) for a variety of reasons that are all centred around protecting their eyes. The most common reasons include:

• managing conditions, such as equine recurrent uveitis, headshaking or photosensitivity
• UV protection 
• glare reduction, improving a horse’s vision in bright conditions
• extra protection during recovery from injury or surgery
• high-risk sports, to prevent injuries from flying dirt kickback or balls, for example

Just like humans, horses benefit from the protection sunglasses, goggles and visors offer from harmful UV rays and sun glare. Horses with little or no pigment in the skin around their eyes are particularly vulnerable and can suffer from sunburn, squinting, watery eyes, sunburn, cataracts, and even cancer.

When can a horse wear sunglasses?

Unlike fly masks, equine sunglasses, googles or visors of any kind should only be worn when ridden or supervised. This is because of the potential for them to move or get caught if a horse rubs their face.

Visors are not permitted to be worn in competition by many governing bodies (including British Dressage, British Eventing and British Showjumping), so it’s recommended that you check individual rulebooks first. They are permitted in some cases by the British Horse Racing Authority, but must be declared in advance.

Googles, visors and sunglasses are, however, also marketed for use in the following sports and areas of equestrianism across the world:

• hacking or trail riding
• barrel racing
• eventing or cross-country
• showjumping
• endurance
• racing
• polo, including snow polo
• mounted shooting protection
• skijoring

Types of sunglasses for horses

Some visors – those with transparent lenses – only serve to protect a horse’s eyes from trauma, which could be caused by flying dirt or other objects.

Goggles or sunglasses with tinted lenses offer varying levels of light blocking, although this is not the same as UV protection. Horse sunglasses are also assigned filter categories (just like human sunglasses) depending on the strength of the filter, ranging from zero to four, with category four being the darkest.

Below are one model’s (the eQuick eVysor) visible light transmission percentages for their available tinted lenses, along with the filter categories for context.

• Transparent: 98.08%, category 0
• Mirrored orange: 46.28%, category 1
• Mirrored blue: 42.64%, category 2
• Mirrored green: 38.41%, category 2
• Mirrored rainbow: 19.85%, category 2
• Darker: 10.45%, category 3

Visors typically fit over the ears and secure under the jaw. Some have elasticated straps to make them easier to put on and take off.

Visors for police horses

While Horse & Hound has previously reported on a police horse who wore sunglasses for medical reasons, some situations require mounted police horses to wear specialist visors that protect the eyes and nose from objects thrown in a public order or riot situation. These are category zero glasses designed purely for trauma protection rather than light reduction.

• For unlimited access to the latest product news, buying guides and reviews, subscribe to the Horse & Hound website

You might also enjoy:

Police horse wows Royal Ascot in designer sunglasses: ‘People seem to love them!’

Equine eyesight questions answered, plus vets share advice on common vision problems to look out for

7 famous one-eyed horses who have excelled in their careers

Equine recurrent uveitis (moon blindness) in horses

How to avoid your horse suffering from sunburn this summer

Tried and tested sun creams for protecting your horse’s pink skin this summer

Subscribe to Horse & Hound magazine today – and enjoy unlimited website access all year round

You might be surprised to find out that there are many famous one-eyed horses who have been hugely successful at the top level of equestrian sport. One-eyed and partially sighted horses have reduced eyesight due to a wide range of eye problems or accidents.

Famous one-eyed horses

Briarlands Blackberry

Eventer Izzy Taylor contested Blenheim, Burghley, Bramham and Barbury with Briarlands Blackberry, who lost an eye two years before she took the reins.

“Sat on top, you wouldn’t know he only had one eye,” she says. “The only time I suspected it affected him was at Bramham when, unusually for him, he had a run-out at a coffin with a slanting rail on his blind side.”

Santana

The dressage stallion by Sandro Hit lost his left eye after scratching it in his stable in 2009. Treatment couldn’t save it so the eye was removed.

However, it didn’t stop him competing at the top level. He took part in the 2012 London Olympics with Minna Telde of Sweden. The team finished fifth.

In May 2014, the pair won the grand prix and special at Hamburg CDI4*.

Adventure De Kannan

Adventure De Kannan, the famous “one-eyed wonder horse” won the 2014 Hickstead Derby having finished runner-up the previous year.

The “one-eyed wonder horse” graced the cover of Horse & Hound after Hickstead, as well as being featured in mainstream media after winning by just 0.02sec in the jump off — ahead of the 2013 winners Phillip Miller and Caritiar Z.

The gelding had his right eye removed in 2013 due to a long-term infection. And it clearly had no adverse effect.

“He’s got an enormous heart,” says Trevor. “He does everything I ask him to whether he can or not, and if he can’t he’ll try anyway.”

H&M Tornesch

Showjumping stallion H&M Tornesch had battled an issue in his right eye for years before he injured it further in 2013 and it was removed. He competed at CSI5* level for many years with Swedish rider Malin Baryard-Johnsson. She said it was all down to trust.

He originally had about 30% vision in the eye, but in 2013 he damaged it while breeding and it couldn’t be saved.

The Dutch Warmblood wasn’t set back, though — competing at CSI5* level until his retirement from top class competition in January 2016.

Patch

Racehorse Patch contested the Kentucky Derby and finished third in the Belmont Stakes in USA.

An Cathaoir

One-eyed former racehorse An Cathaoir and Victoria Bertorelli landed the 2025 Tattersalls Retraining of Racehorses (RoR) amateur ridden championship at Hickstead.

“He’s my one-eyed legend,” said Victoria.

Material World

The Suzy Smith-trained mare (right) won five times despite losing an eye after an accident on the gallops before her career even began.

“Daisy” was training when she had to avoid a jogger coming in the opposite direction, slipping and falling. She then developed a fungal infection in her eye and had to have it removed.

Her final race was as a 10-year-old in the 2008 World Hurdle at Cheltenham before becoming a broodmare.

You may also be interested in:

How to train, ride and manage a partially sighted horse: advice from owners with experience

Equine eyesight questions answered, plus vets share advice on common vision problems to look out for

‘He’s completely blind in one eye’: Appaloosa defies the odds to win Windsor for the 7th time

Totally blind horse takes to the dressage arena

Elizabeth hopes that Rio will inspire other riders of partially sighted or blind horses not to give up on them

Subscribe to Horse & Hound magazine today – and enjoy unlimited website access all year round

We all know that horses are incredible animals but none more so than when it comes to adapting to life with limited eyesight. Partially sighted, one-eyed and even blind horses have proved time and again how adaptable they can be, with many competing successfully in the top tier of the sports of racing, showjumping, eventing and dressage, despite limited eyesight or vision.

So whether a horse has been born with a limiting eye condition, or has lost an eye through injury or common eye disease, how do you train or retrain a partially sighted horse? How can you help them in their daily lives after such a life-changing event? We asked those with experience for their expert opinions.

How to help partially sighted horses: a case study

South Yorkshire-based showjumper Jessica Hayes, who runs Belton Sport Horses, is currently producing the “very special” four-year-old Humoso, AKA Bazil, who was born with a condition that meant he’s only had vision in one eye from birth.

His breeder Dawn Slater approached Jess last year, asking if she’d take on her beloved youngster, who’d been assessed by vets and she’d been told that he should be able to live a very normal life, despite having no vision in his right eye.

“Dawn told me, ‘This is his drawback, I just want somebody to give him a chance,” recalls Jess. “I said I’d pick him up tomorrow!

“Obviously we had to consider how we were going to train, manage and treat him – the vets had said that hopefully he would adapt well as he’s never had sight in one eye, but that’s easier said than done because he cannot see us at all on his left-hand side, so do we still lead him, mount him and break him in from the left?

“I’d love Bazil to stay with us for the rest of his life but, if he ever needed to do a different job or go to a different home, we needed to give him every chance of having a normal life in a normal home. So we thought ‘OK, we’ll just do everything from the left’ and we did it.

“Flying by the seat of our pants is the best term for what we’ve done!” says Jess, who was helped in the backing process by Jakob Bartlett. “It’s been a huge learning curve because he’s had to adapt to us and we to him.

“The key to helping him as a partially sighted horse is being very vocal and very hands on with the patting, the rewarding and the reassurance. You can see his ears twitching as he listens. I think he has a personality where he tries that much harder – he absolutely loves his job – which also helps.”

Partially sighted horses may naturally have a tendency towards sharpness and Jess says that’s the case with Bazil but “he harnesses that in a positive way” she says of the gelding by Chrysler Key SR x Quidam.

“He’s very sensitive to ride but he does it all himself – flying changes and I cantered him over poles for the first time last week and he travelled down them on the biggest, bounciest, level canter like these poles were nothing. I just thought ‘Wow’.”

Teaching a partially sighted horse to jump seems daunting, but Jess lay the foundations early on with Bazil.

“Every time I ride him, I lay poles around for him to walk or trot over – often tight off the corners so he’s always thinking ahead, looking for them and learning to judge them,” she explains. “I thought that was the best thing I could do for him at this early stage where we’re keeping everything easy and basic for him, so by the time he’s jumping a course, he’ll come off the bends looking for the poles – it’s part of his routine now. He’s had a little jump under saddle and the bolder and brighter the filler is underneath, the better he jumps. I don’t think he’s going to be spooky!

“We’re training his mind and his eye to see and judge as best we can.”

Jess says that riding Bazil doesn’t feel much different to fully sighted horses other than he occasionally wants to tilt his head.

“I use my voice, put a bit of leg on and encourage him and he goes ‘OK, I get this, I’ll keep listening to you’ – his full trust is in us,” says Jess. “When I hacked him out for the first time, we passed tractors and all sorts, but he was so good. He gets turned out every day with my mare, he loads well, he just does everything!

“I don’t think he knows he’s blind. We haven’t told him and people laugh when I say that but this has been him since birth so he doesn’t know any different. As long as we don’t treat him differently we won’t let the cat out of the bag and we can carry on as normal.

“Of course, it’s been challenging but so rewarding – all my reservations and concerns have been blown out the water,” adds Jess who hopes to take Bazil to the Met Tour in Spain in the spring to contest some of the five-year-old classes with a view to producing him to a top-level showjumper alongside her other horses.

“I’d like him ultimately to be one of those horses who can hold his own on the global stage – whether that’s with me or someone else,” she says.

Flipper Darco UK Z

Jennifer Billington’s top showjumping horse Flipper Darco UK Z is blind in one eye but has been a “horse of a lifetime” for his young rider, jumping at London Horse Show, Bolesworth and representing Great Britain at the junior and young rider Europeans.

“He runs off trust,” says Jennifer. “He needs complete confidence in the rider, especially if you’re coming to a water tray – he was shy and spooky with me in his early days, but that perseverance has paid off. Coming off a left turn in a jump-off, I always try to make sure I’m straight enough to allow him to see the fence, but otherwise it doesn’t affect him at all, it’s amazing.”

Flipper Darco’s breeder Caroline Phillips says, “I knew he was blind in one eye from a three-year-old, so when I backed him and rode him, I taught him to listen to my body and understand the turns by riding him round bending poles. He is the most amazing horse I’ve ever ridden.”

How to help partially sighted horses

There are some practical steps you can take to help partially sighted horses in their daily life.

• Provide a safe environment with padding on any sharp edges
• Keep to a familiar, safe routine
• Turn out in the field with a quiet, calm companion
• Place haynets, feed and water buckets in the same position, ideally against a wall or solid object
• Introduce new environments quietly and slowly

With time and a little extra consideration, partially sighted horses have just as much chance as any other horse to life a happy life with a successful career.

Do you have any more top tips for looking after horses with limited vision? Let us know your experiences with partially sighted horses by emailing hhletters@futurenet.com with your name, nearest town and county

• To stay up to date with all the breaking news from major shows throughout the year, subscribe to the Horse & Hound website

You may also be interested in:

Equine eyesight questions answered, plus vets share advice on common vision problems to look out for

‘She’s incredible’: meet the pocket-rocket thoroughbred winning with one eye

7 famous one-eyed horses who have excelled in their careers

Examining the equine eye *H&H Plus*

What does an ophthalmic exam entail? Ria Chalder MRCVS explains all

Subscribe to Horse & Hound magazine today – and enjoy unlimited website access all year round

Horses have one of the largest eyes of any mammal, but how good is horse eyesight compared to ours? And what common problems should horse owners be ‘keeping an eye out’ for?

We’ve got all the information you need on equine vision and eyes right here – plus some advice from expert vets on how to spot an equine eye problem.

Do horses have good eyesight?

Horses are prey animals and have almost 360° vision – their only blind spots being beneath their chin and directly behind them – so that they can watch out for predators approaching from all directions at the same time as grazing.

They have good motion detection, which allows them to spot predators easily, and have better night vision than humans. Their ability to judge distance and depth is limited, especially as most of their field of view is monocular vision (with one eye), which is why they often raise their heads on approach to a fence. It also takes them longer to adjust from light to dark.

They have developed big, beautiful eyes that protrude from each side of their head. However, this also makes them more exposed, and therefore more vulnerable to blunt or sharp traumatic injury.

Can horses see in colour?

Imogen Johns FRCVS explained to H&H that it is “next to impossible to say for sure how ‘well’ a horse can see”, but we know that horses are dichromats, which makes them red-green colour blind. They can see blues and yellows but browns, oranges and shades of red and green are easily confused. Whereas humans, for example, are trichromats and can see the four basic colours of red, green, blue and yellow.

Horses are able to see very well in low light conditions, but need time to adapt from light to dark situations and vice versa, which is why jumping into and out of shaded areas is such a challenge when riding cross-country.

Signs of sight loss in horses

Karen Coumbe MRCVS told H&H what to look out for to keep your horse’s vision safe. Any sign of ocular pain in horses is always deemed an emergency and a prompt visit from your vet should be arranged if there is:

• An eyelid wound
• A closed or partially closed eye
• Discharge or pus coming from the eye
• A swollen eye or eyelid
• A reddened appearance
• An eyeball that suddenly turns cloudy or develops a discoloured area
• A painful eye, especially if there is also increased sensitivity to light

“A problem affecting one eye only can be an indication of something more serious,” says Karen Coumbe. “Always look out for other more subtle signs, such as downward-pointing eyelashes indicating a partially closed eyelid, or other subtle signs of eye trauma, such as discolouration.”

Causes of sight loss in horses

Ocular injuries generally result from impact, a penetration or an abrasion/laceration and among the most common injuries are abrasions of the globe (which can lead to the formation of a corneal ulcer) and periorbital lacerations (traumatic injuries sustained around the eye).

“To prevent problems, it is important to check your horse’s environment, minimising anything that could potentially injure them, such as thorny vegetation, protruding nails and rough edges around stabling,” says Karen. “Horses often rub their heads on any solid object available, especially during fly season. Interactions with other horses may increase the risk of eye injuries.”

Fly masks and horse sunglasses can be worn to prevent irritation and reduce the risk of injury – and they can provide UV protection, too.

Common horse eyesight problems

Other common horse eye problems that can potentially affect their vision include uveitis (also known as moon blindness) and immune-mediated keratitis. Uveitis means inflammation within the eye and is the most common cause of blindness in horses worldwide and a common cause of chronic eye pain.

Some horse eyesight problems are more common in older horses, including glaucoma or cataracts, or can be more serious, such as corneal disease.

The aim of veterinary treatment is always to save the eye. However, if this cannot be done or if the horse is going to be left with a chronically painful eye, then enucleation (removal of the globe) is a relatively uncomplicated surgery that can be performed. Horses and ponies tolerate the loss of an eye extremely well and appear to adapt easily – many are still able to be ridden, including jumping, after such a procedure.

Can horses cope with loss of vision?

Loss of vision in one eye is generally very well tolerated by horses – most horses are able to return to their “pre-enucleation” job

Loss of vision in both eyes is rare – while some blind horses do adapt, the personality of the horse, the facilities, environment, and input of the owner will all determine how successful the outcome is.

Can blind horses be trained?

Absolutely, training partially sighted horses and blind horses just requires a slightly more considered approach and there are many famous one-eyed horses who have gone on to have incredibly successful careers.

“Endo the Blind”, a US-based appaloosa gelding owned by Morgan Wagner, became famous for his spirit, showing that “blind horses are capable of anything” by claiming three world records aged 22.

At the age of eight he’d been diagnosed with glaucoma, cataracts and equine uveitis, but his record-breaking achievements included the highest free jump by a blind horse (106cm), the fastest time for a blind horse to weave five poles (9.93sec) and the most flying changes in a minute (39).

“Don’t have big goals, just what your horse can do, reward, and try a little bit more next time,” said Morgan.

An Italian racehorse named Laghat won 26 races despite being totally blind in his right eye and 95% blind in his left eye as a result of a fungal infection called mycosis.

“Laghat has a sixth sense, which tells him where to put his legs,” said owner Federico de Paola, who also rode the horse in amateur races.

• For unlimited access to advice on how best to care for your horse, subscribe to the Horse & Hound website

You may also be interested in:

How to train, ride and manage a partially sighted horse: advice from owners with experience

All you need to know about the equine eye *H&H VIP*

Our new occasional series zooms in on the equine eye. Looking into this complex device can offer vital clues about

Equine recurrent uveitis (moon blindness) in horses

4 common eye problems in horses and how to treat them

Stay on the look out for these common eye problems in horses

7 famous one-eyed horses who have excelled in their careers

Subscribe to Horse & Hound magazine today – and enjoy unlimited website access all year round

An “incredible” sixth-generation pocket-rocket thoroughbred who had her eye removed towed her rider round the British Eventing novice at Frenchfield (2) to take the win on Saturday (9 September).

Charles and Gilda Brader’s home-bred Doubled Duchess and Nicola Mason topped their section by adding just 1.6 cross-country time-faults to their 29.8 dressage.

Nicola has been riding the mare, who is “15.2 and a half” hh, since she was a six-year-old, and competed her up to intermediate level. Then at the start of 2021, when “Ruby” came back from her winter holiday, aged nine, she had a weepy eye.

“The vet gave me some eye drops and said she’d be fine,” Nicola told H&H. “But five days later, she wasn’t really any better. The vet came back and said he wasn’t sure but gave me some stronger stuff. And it went on and on from there.”

Ruby had “all sorts of treatment”, Nicola said, and vets determined the probable cause of the issue was that she had picked up a virus, which had caused immune mediated keratitis.

“So her own immune system was attacking her eye,” Nicola explained. “Removing it was always an option but the vets said they couldn’t guarantee her body wouldn’t attack her other eye afterwards.”

Steroid treatment did stabilise the condition, but then it stopped responding.

“She’s such a stoic little mare, she likes to let her opinion be known,” Nicola said. “She’s feisty, but then she went very quiet and was standing in the back of her stable. Every time we’d got it under control, it had flared up, and we’d worried about it for so long but in the end, the decision almost made itself.”

Nicola said the surgery itself was very simple.

“It was incredible,” she said. “They did it standing, with me holding her head, in her own stable. I thought how fantastic; if you’re going to wake up missing an eye, surely you’re better off in your own stable rather than in hospital, and she was very good, it was remarkable how she coped with it.”

Ruby had a dressing on for two weeks, after which the eye socket was looking good, Nicola said.

“Then she had the staples out and I said ‘What now?’” Nicola said. “The vet said: ‘Ride her!’

“So I put the tack on and she didn’t feel any different.”

Nicola said she has noticed some changes and made some adaptations, such as always loading another horse before Ruby, so she can see it and know she is not alone. The mare is also different going through gates, as she can judge things better from further away.

“It was her nearside eye so she’s done a bit of standing on my foot – but that’s possibly slightly on purpose!” she said.

Ruby came back into work in time for a couple of events that season. She had a quieter year in 2022 as Nicola had a fall from a youngster at home and suffered concussion, and has been competing at novice level this year.

“When we started, she wasn’t keen on horses approaching on her blind side in the warm-up but now she’s fine,” Nicola said. “She’s had a couple of little blips where she’s dithered coming down a step, or down into water, which is something she’s had to relearn, but she’s pretty incredible, and that’s mostly behind her now. She was on fire at Frenchfield!

“She’s the sort of horse who’s easy to read; you know when she’s grumpy or happy and she towed me round the cross-country on Saturday; she squeals and bucks and loves it. Our attitude has been wait and see and the more we’ve done, the more amazing we think she is and she still wants to do it, which is brilliant.”

You might also be interested in:

Thoroughbreds to be recognised at Olympics, but still can’t contest World Breeding Championships

‘He lost his eyes but not his spirit’: blind horse takes three world records

Subscribe to Horse & Hound magazine today – and enjoy unlimited website access all year round

Horse & Hound magazine, out every Thursday, is packed with all the latest news and reports, as well as interviews, specials, nostalgia, vet and training advice. Find how you can enjoy the magazine delivered to your door every week, plus options to upgrade your subscription to access our online service that brings you breaking news and reports as well as other benefits.

Stay in touch with all the news in the run-up to and throughout the major shows and events during 2026 and beyond with a Horse & Hound subscription. Subscribe today for all you need to know ahead of these major events, plus online reports on the action as it happens from our expert team of reporters and in-depth analysis in our special commemorative magazines. Have a subscription already? Set up your unlimited website access now

The organiser of a showing class for horses who are ruled out of affiliated competition by abnormalities hopes the idea will spread.

Jackie Coultas is behind the unaffiliated “Impaired horse or pony, in hand or ridden” class at Malton Show on Sunday (25 June). It is open to mares or geldings of any age, who “may have impairments” that do not affect their welfare but mean they are unable to compete under society rules.

Jackie told H&H that in the course of her work as a horse transporter, she has seen many horses and ponies with one eye.

“I thought they’re too good not to have a show career,” said Jackie, who also stewards and judges. “Some of them are such quality; I know a cracking show pony who had to have his eye out as another one bit it, and a lovely young Dales who had his eye out too. I run horses to the vet in my job, and it got me thinking.

“It’s through no fault of their own, and I’d like to give them that recognition in the show ring.”

Jackie said she had had a lot of interest and good feedback, and if this “tentative” first attempt goes well – she added that other shows have also expressed interest – she may try to create a series and final in future.

“I think it will give people confidence, get them back in the show ring, and bring the fun back,” she said.

You might also be interested in:

Hickstead crowds say fond farewell to one-eyed wonder horse

Showjumping fans gave Adventure De Kannan a rousing reception during his official retirement ceremony at Hickstead

One-eyed top event mare delights with sparkling performance on return from injury

Subscribe to Horse & Hound magazine today – and enjoy unlimited website access all year round

Horse & Hound magazine, out every Thursday, is packed with all the latest news and reports, as well as interviews, specials, nostalgia, vet and training advice. Find how you can enjoy the magazine delivered to your door every week, plus options to upgrade your subscription to access our online service that brings you breaking news and reports as well as other benefits.

Stay in touch with all the news in the run-up to and throughout the major shows and events during 2026 and beyond with a Horse & Hound subscription. Subscribe today for all you need to know ahead of these major events, plus online reports on the action as it happens from our expert team of reporters and in-depth analysis in our special commemorative magazines. Have a subscription already? Set up your unlimited website access now

A protocol for treating dry eye problems in humans has been successfully adapted for horses and it is hoped more animals could benefit.

Helen Newlands’ 26-year-old gelding Ryan has struggled with a chronic eye issue for some time. Ryan, who was otherwise healthy and bought as a six-year-old for low-level eventing, first presented with a weeping and closed eye, and was found to have ulceration on the surface.

Helen told H&H Ryan started treatment under the Dick Vet Equine Hospital in Edinburgh, and for periods of time his eye would improve, but the ulcers continued to return. After seeing an equine ophthalmologist Ryan was diagnosed with immune mediated keratitis (IMK), and following a course of treatment he went into remission, but again, the ulcers came back.

“In 2016 we went through a really difficult time,” Helen said. “It would clear up, ulcer, clear up, ulcer.

“We saw the ophthalmologist again and it was suggested we try debriding the cornea, to almost reset it. It seemed to help, but then three months later he got another ulcer.”

Helen said there were conversations about removing Ryan’s eye, but in early 2021 vet Susie Armstrong sat down with human ophthalmologist Fraser Peck to review Ryan’s case. Focus was placed on Ryan’s meibomian glands, which produce lipids that form the surface lipid layer of the tear film. When the tear film becomes defective, the surface of the eye can become dry and the result can be ulceration.

A human treatment protocol for dry eyes was adapted for Ryan and he started the new regime in March 2021. This involved daily hot compresses, and the use of a lubricant, serum and topical antibiotic.

“We started getting excited after six months. Ryan wasn’t getting anything recurring, and we seemed to be getting somewhere,” said Helen.

“He remained under review and would go into the hospital to check his meibomian glands every so often. They also performed tear film tests and could see that his tear film was improving, which meant his dry eye was improving”.

Ryan will remain on the regime indefinitely, and although he has had the occasional ulcer since, these have cleared up quickly. Helen said his quality of life has improved and he continues to enjoy hacking in his retirement.

“He was out 24/7 during the summer, and I can’t remember the last time we were able to do that because we used to be too nervous to leave him out in case he came in with an ulcer,” she said.

“I’ve had the same yard owner, Pammy Stevens, for 20 years and without her support I wouldn’t have gotten through it all. It was emotionally draining, it was upsetting, and financially it was difficult. His eye was only insured for one year so I’ve spent thousands over the years, but this new regime is inexpensive.”

Helen said Susie has been “so committed” to helping Ryan, and this year she nominated her in the Petplan Veterinary Awards.

“Susie first came to see Ryan in 2016 as a locum, and she’s absolutely changed everything for us,” she said.

Susie, who was a lecturer in equine practice at the University of Edinburgh and is now a senior lecturer in veterinary clinical research at the University of Surrey, published Ryan’s case in VetRecord CaseReports last year. She has presented lectures on the protocol internationally, which have been met by veterinary experts positively.

“The protocol is not groundbreaking in itself, but what we’ve done is adapted the human protocol for use in animals. We have always put eye issues like these to mechanical problems for example with their eyelid, or there has been an underlying infectious component that continues to cause these ulcers,” she said.

“We’re now working towards better objective tests to support clinics and practices who maybe don’t have all the tools they need to make these diagnoses. We’re starting to change the narrative to look at the tear film when looking at eyes, which we didn’t previously do.”

Susie added that removing a horse’s eye is generally the last option, and in Ryan’s case, “it never crossed the ethical line that he would be better without his eye”.

Susie said Ryan’s case has been a “success story”.

“It’s led to us thinking what else can we do,” she said. “The protocol is being rolled out in small animals and there are people around the globe implementing the protocol in other equine cases. We’re waiting to gather all the data and we plan to publish a case series.”

You might also be interested in:

‘I’ve really missed him’: young horse who lost eye makes winning competition return

4 common eye problems in horses and how to treat them

Stay on the look out for these common eye problems in horses

Subscribe to Horse & Hound magazine today – and enjoy unlimited website access all year round

Horse & Hound magazine, out every Thursday, is packed with all the latest news and reports, as well as interviews, specials, nostalgia, vet and training advice. Find how you can enjoy the magazine delivered to your door every week, plus options to upgrade your subscription to access our online service that brings you breaking news and reports as well as other benefits.

Stay in touch with all the news in the run-up to and throughout the major shows and events during 2026 and beyond with a Horse & Hound subscription. Subscribe today for all you need to know ahead of these major events, plus online reports on the action as it happens from our expert team of reporters and in-depth analysis in our special commemorative magazines. Have a subscription already? Set up your unlimited website access now

A horse who lost both eyes but not his spirit has shown that “blind horses are capable of anything” by taking three world records, aged 22.

US-based Morgan Wagner’s appaloosa gelding Endo, who has become famous as Endo the Blind since he lost his sight, has secured the Guinness records for the highest free jump by a blind horse, clearing 106cm, the fastest time for a blind horse to weave five poles, 9.93 seconds, and the most flying changes by a horse in a minute – 39.

Megan has owned Endo since she was 13 and he was a foal. When he was eight, she noticed he seemed to be squinting, and that his eyes wept in summer and appeared painful. He was diagnosed with , glaucoma and cataracts, and equine recurrent uveitis, a leading cause of blindness in horses.

Despite the best efforts of Morgan and her vets, after five years, Endo’s right eye ruptured and had to be removed. Within months, it became clear that he would also have to lose his left eye.

“Knowing that Endo was facing a life without sight, Morgan was determined to prepare him for what was to come,” a Guinness World Records spokesman said. “Reassuring and petting him, Morgan would blindfold Endo to acquaint him with the feeling.”

Despite all the preparation, losing his left eye was a big step.

“He was very scared in the beginning, so I took him for walks around the barn and then moved on to walks around the property,” said Morgan. But with her support, he regained his confidence, and can now do all a sighted horse would, including competing, hacking, jumping and liberty work.

Morgan hopes Endo’s story will inspire others to focus on the abilities of blind horses rather than their differences.

“Don’t have big goals, just what your horse can do, reward, and try a little bit more next time,” she said, adding that she wants everyone to know how proud she is of her horse, “not just because of his record-breaking achievements, but because despite losing his eyes, he never lost his spirit”.

“I’m very grateful to Guinness World Records for letting us have a platform for blind horses to show the world that they’re still capable of anything,” she said.

You might also be interested in:

Totally blind horse takes to the dressage arena

Elizabeth hopes that Rio will inspire other riders of partially sighted or blind horses not to give up on them

One-eyed Hickstead legend to retire at this year’s Derby

'I didn’t think it was fair to him to keep going, and I don’t want to be unfair to a

Subscribe to Horse & Hound magazine today – and enjoy unlimited website access all year round

Horse & Hound magazine, out every Thursday, is packed with all the latest news and reports, as well as interviews, specials, nostalgia, vet and training advice. Find how you can enjoy the magazine delivered to your door every week, plus options to upgrade your subscription to access our online service that brings you breaking news and reports as well as other benefits.

Stay in touch with all the news in the run-up to and throughout the major shows and events during 2026 and beyond with a Horse & Hound subscription. Subscribe today for all you need to know ahead of these major events, plus online reports on the action as it happens from our expert team of reporters and in-depth analysis in our special commemorative magazines. Have a subscription already? Set up your unlimited website access now

A promising young dressage stallion who had to have his right eye removed owing to uveitis has made a winning return to competition after nine months off.

Grand prix dressage rider Fenella Quinn and her mother Jacqui Ross bought Daily Diamond son Mambo Chachacha at six weeks old at an auction in the Netherlands in 2017. He remained abroad while he grew up and was backed, then moved to Fenella’s Aberdeen-base to continue his education.

“At the auction it was like Mambo picked us. We had planned on bidding on him anyway, but he left his mum and came trotting directly to our table and I remember the auctioneer saying ‘It looks like he wants to go home with you’,” Fenella told H&H.

“When he came home aged three he was just perfection from day one. I couldn’t believe how easy he was and how balanced. He was just a dream in every way.”

Last year Fenella campaigned Mambo in the British Dressage young horse series and the pair qualified for the semi-final at Hartpury, where they were 16th in the four-year-old class.

“After we got back from the semi-finals everything started to go wrong,” said Fenella.

“Mambo got uveitis quite severely and quite quickly. Immediately we got our vets, Ardene House Equine Vets, and they referred us to Ben Blaclock, an ophthalmologist at the Royal Dick Vet in Edinburgh. We went through treatment plans and Mambo was put on quite aggressive treatment. Over the next few months it would clear up but then flare up again and it was really hard to keep on top of.”

In September Mambo was fitted with a special implant behind his eye in the hope this would get on top of the uveitis.

“We thought this would be the last port of call, but unfortunately for us we were one of the eight per cent of cases where it didn’t work. The uveitis came back so aggressively and the ophthalmologist said he had never seen a case as aggressive as Mambo’s,” said Fenella.

“We were treating him with eye drops eight times a day, he was off work because he was sore, and he couldn’t go in the field because we had to try to keep everything dark.”

Fenella said despite continued treatment and trips to the vets in Edinburgh, it was decided that the “kindest thing to do” was to remove Mambo’s eye.

“It was really difficult and a horrible decision to have to make when he’s so young and so talented. You have no idea how they are going to adapt – he’s such a sweetheart but you wonder if they will change, or become spooky and nervous. You just don’t know how they’re going to take it, but there really was no option and we couldn’t stand to see him struggling,” she said.

“The operation took place in November and then we began the healing process of trying to get him used to life without an eye.”

Fenella said throughout the treatment and following the operation Mambo has been a “sweetheart” and “adapted incredibly well”.

“He’s been unbelievable the whole way through. He’s never been difficult, and he’s taken to only having one eye so well. He had nine months off work overall but it’s like he’s never been off,” she said.

“To start with we wouldn’t approach him from the right side and we talk to him a lot so he always knows where you are. When I get on I always start on the right rein first so his left eye can see the wall, and give him a chance to get his bearings.”

Fenella – who has a string of horses from youngsters up to grand prix level – has high hopes for Mambo and believes he could be a grand prix horse in future. On 13 August he returned to competition for the first time since and won both his novice classes on scores of 70.32% and 71.88% at Tillyoch Equestrian.

“I didn’t really know what to expect because we’ve not been away from home recently apart from going to the vets, but he didn’t put a foot wrong and did two gorgeous tests,” said Fenella.

“Of all my horses he’s probably the one that excites me most about the future. His talent is phenomenal, he’s just incredible. He has the sweetest nature and you would never know he’s a stallion, he’s is in a barn with my mares and I can ride him with mares.”

Fenella plans to take Mambo to some more local shows over the winter, and next year hopes to do some Premier Leagues.

“I have no plans to rush him, no matter how talented he is. But now we can get going again which is great because I’ve really missed him.”

You might also be interested in:

‘I saw my life disappearing in front of me’: how one rider got back in the saddle after a crushing fall

Dressage rider Fenella Ross shares her story of how she came back from a fall that broke her back to

‘It was absolutely terrifying’: owner shares uveitis experience that nearly took her horse’s life

17hh gelding Chance was first diagnosed with the disease last July

Equine recurrent uveitis (moon blindness) in horses

Horse & Hound magazine, out every Thursday, is packed with all the latest news and reports, as well as interviews, specials, nostalgia, vet and training advice. Find how you can enjoy the magazine delivered to your door every week, plus options to upgrade your subscription to access our online service that brings you breaking news and reports as well as other benefits.

Stay in touch with all the news in the run-up to and throughout the major shows and events during 2026 and beyond with a Horse & Hound subscription. Subscribe today for all you need to know ahead of these major events, plus online reports on the action as it happens from our expert team of reporters and in-depth analysis in our special commemorative magazines. Have a subscription already? Set up your unlimited website access now

A Riding for the Disabled Association (RDA) pony is adapting to a new way of life after having his eye removed.

Last Monday (17 January) when the team at Cotswold RDA went to get the ponies in at 8am for their lessons, 18-year-old gelding Chester was standing alone. Holly, one of the grooms, went to Chester and discovered he had severe damage to his eye and Cheltenham Vets were called.

“As soon as the vet saw him she said the eye had burst and there was absolutely no way to repair it. We think he was kicked by another pony,” Lesley Gorton, the group’s general manager, told H&H.

“It was obviously a very traumatic day because we still had our clients to look after, while Chester had his eye removed but the vets were absolutely amazing and did a great job looking after Chester – and us.”

Lesley said Chester was very “jumpy” following his operation but the 12hh pony is now regaining his confidence.

“We made sure only a couple of people were dealing with him to start with as he was quite unsure of himself but now he’s doing well and adapting – you can tell he’s much more confident. He very much thinks he’s king of the castle because people have been bringing him carrots and apples,” she said.

“We’re hoping in another week he’ll be able to start some gentle work again and we’ll reintroduce him to the indoor school to see how he copes with the surroundings.”

The group has created a “Chester fund” to raise some money to cover the gelding’s vet fees. Donations can be made via the group’s Facebook page or website.

“Every single donation makes a huge difference and we are hugely grateful. Chester is much loved by many children and has a lovely character so we hope he can continue being the wonderful pony he always has been, working again in the near future,” said Lesley.

You might also be interested in:

Waiting lists grow as struggle to find suitable RDA horses and ponies continues

93-year-old has her first ride, on 31-year-old mare, with a glass of wine to follow

Subscribe to Horse & Hound magazine today – and enjoy unlimited website access all year round

Horse & Hound magazine, out every Thursday, is packed with all the latest news and reports, as well as interviews, specials, nostalgia, vet and training advice. Find how you can enjoy the magazine delivered to your door every week, plus options to upgrade your subscription to access our online service that brings you breaking news and reports as well as other benefits.

Stay in touch with all the news in the run-up to and throughout the major shows and events during 2026 and beyond with a Horse & Hound subscription. Subscribe today for all you need to know ahead of these major events, plus online reports on the action as it happens from our expert team of reporters and in-depth analysis in our special commemorative magazines. Have a subscription already? Set up your unlimited website access now

A clever surgical technique can restore full function to the eyelid after growth removal, as Andrea Oakes discovers

SKIN masses, such as melanomas, sarcoids and squamous cell carcinomas, can be particularly troublesome when they appear in close proximity to the eye. Left untreated, a mass may grow and interfere with eyelid function or vision. Yet treatment can result in damage to the thin skin of the eyelid, inhibiting its ability to protect the eyeball and to keep it bathed in lubricating tears.

While nine-year-old Irish Draught/thoroughbred mare Rosie appeared unbothered by a cluster of ulcerated masses developing at the outer corner of her left eye, vets at Pool House Equine Clinic in Staffordshire felt that these growths were best removed.

“Treatments such as chemotherapy and radiotherapy are sometimes possible, depending on the nature of the mass, but in this case surgical excision was the favoured option,” says equine surgeon Marco Marcatili. “To preserve the eyelid anatomy and function, and to create a good cosmetic outcome, we planned a reconstructive technique called sliding ‘Z’ dermoplasty.”

DIGGING DEEP

ULTRASONOGRAPHY of Rosie’s eye revealed that the masses penetrated about a centimetre into the deeper tissue layers.

To minimise the likelihood of recurrence after excision, it would be necessary to remove

a significant amount of surrounding tissue during surgery. The aim of “sliding flap” reconstruction is to reconfigure what is left of the healthy tissue, to create less distortion of the skin and a neater scar.

The sliding “Z” flap is just one of a number of flap shape variations, explains Marco. Two triangular areas of skin adjacent to the surgical site are separated from the underlying tissue and removed. The remaining skin flaps are advanced (manoeuvred) into a zig-zag pattern, and the edges are then stitched together with absorbable suture material.

“The surgery is performed with the horse under general anaesthetic, as opposed to standing and sedated, because the surgical instruments are so close to the eye,” adds Marco, explaining that the slightest movement could result in injury.

“We always use ultrasound before surgery to evaluate the full extent of the mass and to plan the excision. Afterwards, the mass is sent to the lab for pathology.”

SEAMLESS REPAIR

FOLLOWING an uneventful recovery from the anaesthetic, Rosie was nursed at the hospital and given antibiotics and anti-inflammatories. Once it was clear that the site was healing without complication, she was allowed home.

“This technique can be very useful to close high-tension wounds following tissue removal,” says Marco, adding that lab tests identified the growths as sarcoids. “All surgery carries some risk, but we usually find that the eye area heals well and fast.”

Six months later, Rosie’s owner, Ellie-Mae Morson, reports that the surgical scar is barely visible.

“She had to wear a fly mask for a few weeks, to protect the area, but after a short time in the stable she could go back out to grass,” says Ellie, who regularly feels along the scar line for any signs of sarcoid reappearance. “Now the hair has grown back, you would hardly know it had happened.”

The sliding “z” flap: how it works

The periocular region (around the eye) is clipped and cleaned, and marked with incision lines.

The masses are excised in their entirety, leaving an area devoid of skin.

Adjacent triangles of skin are removed to let the remaining flaps be drawn across into place.

Suturing completes the reconstruction. Note the tension-relieving incisions behind the site.

The eyelid is fully functioning and already beginning to heal, just 48 hours after surgery.

You can also read this feature in the 13 May issue of Horse & Hound magazine.

You might also be interested in…

Back conformation and saddle fit: what’s new in the veterinary world? *H&H Plus*

Play your part: how to help keep competition horses happy *H&H Plus*

How different grazing systems can help you control your horse’s weight *H&H Plus*

Keeping a veteran active for longer

The teenage rider of a 22-year-old pony who is still enjoying his work having lost an eye wants others to know there is still hope of fulfilling, happy lives for one-eyed horses.

Jessica Venter’s loan pony Peter had surgery to remove his left eye, and although she was concerned, especially at his age, she said he is doing well.

“He was sceptical at first; he’d try to put his head to that side, and I don’t think he understood why he couldn’t see,” she said. “But he trusts me, because I can see for him.”

Jessica first saw Peter, a 14.2hh chestnut, about five years ago, when his owner was looking for someone to loan him. Initially, his owner thought Peter would not be as suitable as Jessica’s other pony, as he was spookier and more excitable, but the pair clicked.

They competed in dressage, cross-country and showjumping, their favourite being jumping, including qualifying for the Sunshine Tour championship at Hickstead.

Then Jessica’s parents bought her a horse, Star, and Peter was loaned to a new home in Wales.

“It wasn’t nice but I understood the owner’s decision,” she said. “Then we had the news he’d had an infection, and had to have his eye removed.

“The owner, and the rider in Wales, decided it would be best for him to come back here; it was nice he was back.”

Jessica researched one-eyed horses and took Peter’s return to work very slowly, but he has coped very well, she said, and still very much enjoys his work.

Continues below…

Ask H&H: one-eyed competition horses

What is it like to care for and ride a horse that is blind in one eye?

One-eyed Hickstead legend to retire at this year’s Derby

'I didn’t think it was fair to him to keep going, and I don’t want to be unfair to a

Subscribe to Horse & Hound magazine today – and enjoy unlimited website access all year round

“I’ve competed him in showjumping, and in dressage, where he surprisingly did better than he did before his eye was removed,” she said, adding that Peter is still jumping at the same height as before.

Jessica added that she wants other riders to know losing an eye is not the end.

“Although there is the disability, and it depends on the horse, it doesn’t mean their ridden career is over for ever,” she said. “I’d like this to give other people hope.”

Horse & Hound magazine, out every Thursday, is packed with all the latest news and reports, as well as interviews, specials, nostalgia, vet and training advice. Find how you can enjoy the magazine delivered to your door every week, plus options to upgrade to access our H&H Plus online service which brings you breaking news as it happens as well as other benefits.

Stay in touch with all the news in the run-up to and throughout the major shows and events during 2026 and beyond with a Horse & Hound subscription. Subscribe today for all you need to know ahead of these major events, plus online reports on the action as it happens from our expert team of reporters and in-depth analysis in our special commemorative magazines. Have a subscription already? Set up your unlimited website access now

A gelding severely injured in a fireworks incident will undergo surgery to have his eye removed tomorrow (10 November) as more than £13,400 has been raised by well-wishers.

Charley Taylor’s 21-year-old gelding Dettori, who she owns with her mother Debbie Walker, was injured in his field at a DIY livery yard in Aberdeen on Thursday evening (5 November) when fireworks were let off nearby.

Charley told H&H she had seen Dettori at 5pm that evening and received a telephone call from her friend Trish Price, who stays at a neighbouring property to the yard, at 8.30pm to say she had seen fireworks going off in the direction of the horses’ field.

“Trish sometimes looks after the horses if we’re ever away so when she saw the fireworks going off she went to check on them and found Dettori with a bloody eye. She couldn’t see his pupil and said all the fencing was down where they had been careering around,” said Charley.

“We went to the yard and got the vet. We won’t know exactly what happened to cause the injury but we think it was a firework. Something impacted Dettori’s eye so much and the vet said there was nothing he could do to save it; it would either have to be removed, or he would have to be put down.”

Charley said she and her mum were “absolutely distraught” at what had happened and the prospect of losing Dettori.

“He is such a big part of our family,” she said. “It was agreed to give him a couple of days to see how he got on with being only able to see with one eye. He’s not old, but he’s not young either and we didn’t want to put him through surgery and the stress of recovery without knowing he would cope ok.”

Dettori, who has arthritis in his hind legs, was kept in a stable following his injury but on the vet’s return the following day it was agreed he needed to stay out.

“He was getting stressed as he struggles to turn in his stable because of the arthritis, and he kept trying to turn so he could see out of his other eye,” said Charley.

“Every little noise was making him jump. He was a horse you could describe as bombproof and now he is jumping at the sound of a car starting. We put him out in the field and he began settling down and seemed to be less stressed having more space to turn.”

Today (9 November) Dettori had a further vet check and it has been agreed to proceed with surgery to remove the damaged eye.

“The vet said Dettori’s eye resembled a ‘flat tyre’ and there really wasn’t an eye to save. He’s become more confident over the weekend and the vet thinks he’ll cope with having it removed. I was crying in relief when he told me,” she said.

“He travelled to the hospital this afternoon and will have surgery tomorrow. Dettori is so loved, I know we’ll get him through this.”

Charley said she spoke to the person who set off the fireworks but said the man did not show any remorse when he was told about Dettori. She reported the incident to Police Scotland.

“In the 10 years we’ve kept horses at the yard we’ve never had an issue with someone letting off fireworks – we’ve never had to think twice about it being a possibility,” she said.

“More than anything I just wanted an apology from the man, I don’t believe he meant to harm the horses but he didn’t say anything.”

Charley posted about the incident online which has received thousands of shares and comments, and was asked by supporters to set up a GoFundMe page.

“We can’t believe the support we’ve had. I’ve had messages from people whose horses have lost an eye, saying how well they have coped which has given us a lot of hope,” she said.

“We hadn’t planned to set up the page and felt quite guilty doing it but so many people asked if they could help towards his vet fees. It’s been overwhelming how much strangers have cared.”

To date more than £13,400 has been donated by well-wishers which will cover Dettori’s vet fees, with the remainder being donated to welfare charities SSPCA and World Horse Welfare.

“The amount raised is crazy! When we saw the total go up we just knew we had to help other animals with it,” said Charley. “We’re now focusing on the positives.”

Article continued below…

More action needed, say MPs, as Government stands firm on firework law *H&H Plus*

Fireworks cause second mare to abort foal: owner vows to campign for change

She was standing on her own, mourning her foal”

Subscribe to Horse & Hound magazine today – and enjoy unlimited website access all year round

In a statement a spokesman for Police Scotland North East Division said the force’s “thoughts are with Dettori”, and that enquiries are ongoing.

“We are working with the owner and those participating in the display,” said chief inspector Darren Bruce. “The intention was never to harm and unfortunately, the result has had tragic consequences for the animal. Although safety measures had been taken, animals whether near to a display or at some distance can be impacted and become distressed.”

Anyone with information in relation to this incident can contact the police on 101 or via the Police Scotland website.

Horse & Hound magazine, out every Thursday, is packed with all the latest news and reports, as well as interviews, specials, nostalgia, vet and training advice. Find how you can enjoy the magazine delivered to your door every week, plus options to upgrade to access our H&H Plus online service which brings you breaking news as it happens as well as other benefits.

Stay in touch with all the news in the run-up to and throughout the major shows and events during 2026 and beyond with a Horse & Hound subscription. Subscribe today for all you need to know ahead of these major events, plus online reports on the action as it happens from our expert team of reporters and in-depth analysis in our special commemorative magazines. Have a subscription already? Set up your unlimited website access now

What does an ophthalmic exam for a horse entail? Ria Chalder MRCVS explains all

You make sure your horse’s feet are trimmed regularly and his teeth are checked routinely, but what about his eyes? Would you know if he was having vision problems?

Several situations call for an equine ophthalmic examination. The most likely is an obvious issue, such as apparent pain in an eye or a change in its appearance. A vet will examine a horse’s eyes during a pre-purchase exam, to look for any abnormalities that may affect his future use or performance. Certain behavioural issues, such as head-shaking, spooking or a recent deterioration in the horse’s confidence, may also warrant an ophthalmic exam.

It is a good idea to arrange an eye check once a year, at the same time as booster vaccinations, so problems can be spotted early and monitored closely.

Assessing vision

An equine ophthalmic examination is very different from what you may have experienced yourself when visiting an optician.

After taking a thorough health history, your vet will observe how the horse interacts with his environment and assess the symmetry of his eyes and face. Any swellings will be noted, as well as abnormalities with eyelid position or ocular discharge.

The angle of the upper eyelashes should be the same on both sides; lashes pointing downwards may indicate pain or a more serious neurological condition. A small amount of clear ocular fluid or dry, black/brown discharge in the corner of the eyes is normal, but excessive fluid or discharge that is white, yellow or green is not, and may signal an infection.

The vet will also check that the third eyelid, termed the nictating membrane, is in its normal position inside the corner of the eye. If it is visible at rest, this may indicate a problem.

Once general observations have been made, the next step is to evaluate the horse’s vision. Determining how much a horse can see is quite challenging. While we may be accustomed to reading aloud the letters we can see on an eye chart, this test of visual acuity, or sharpness, is obviously not an option. Instead, a vet will use a combination of tests to try determine what the horse can see out of each eye in turn.

The first is to assess certain nerve reflexes, or responses to stimulation. If a horse blinks when a threatening hand gesture is made towards his eye, a test known as the menace response, it can be assumed that he could see the hand coming.

Since this protective reaction is developed in the first few weeks of life, a young foal may not have a positive menace response – despite being able to see. The test can also be unreliable if a horse is very anxious, or if nerve damage is preventing him from blinking.

It is important that additional tests are performed and the results are interpreted together. The pupil should constrict, for example, when the vet shines a bright light into the eye. This pupillary light reflex (PLR) reveals more information about the various parts of the eye and brain required for vision.

Inside info

With the hands-off assessment completed, your vet will look more closely at the different parts of the eye using various magnification tools. This stage of the exam should be performed in a darkened stable where possible, to reduce light interference and maximise the amount of observable detail. Sedation may be necessary. Nerve blocks can also be injected under the skin surrounding the eye to paralyse the eyelid muscles, so the horse cannot clamp the eye shut.

A handheld instrument called a direct ophthalmoscope is first used to assess both the retina – the area at the back of the eye which senses light – and the optic disc, where the optic nerve takes information to the brain. At a referral hospital, a head-mounted version of this tool (an indirect ophthalmoscope) will offer a wider field of view. To observe the back of the eye more easily, your vet may administer tropicamide drops to dilate the pupil.

Some vets (especially a veterinary opthalmologist) will also use a slit lamp, which enables much greater magnification and a more in-depth examination of the structures of the eye: the cornea (the clear outer layer at the front), the coloured iris, and the lens, the usually transparent structure located behind the iris. A wide range of conditions can be detected with the slit lamp, including keratitis (inflammation of the cornea), uveitis (inflammation inside the eye) and cataracts (clouding of the lens).

Glaucoma is a condition in which the optic nerve is damaged, usually due to a build-up of fluid that causes high pressure within the eye. While relatively rare in horses, glaucoma can cause blindness. It usually occurs secondary to chronic, repeated episodes of internal inflammation, such as those caused by equine recurrent uveitis.

If glaucoma is suspected, your vet will check the intraocular pressure, or IOP, usually using a rebound tonometer – a handheld device that bounces a lightweight probe off the surface of the eye. The equivalent for humans is a puff of air released onto the eye, known as non-contact tonometry. A high reading in the horse may indicate glaucoma, whereas a low reading may indicate uveitis.

Further tests

If the eye is painful and a corneal ulcer is suspected, your vet may apply an orange dye called fluorescein to the surface of the eye. This harmless liquid turns green and sticks to the parts of the cornea that have lost the top layer, revealing the area of ulceration.

A lack of tears – a condition known as keratoconjunctivitis sicca, or dry eye – may lead to recurrent corneal ulcers or poor ulcer healing. The Schirmer tear test may be used if it is thought a horse is not producing enough tears. For this, an absorbent paper gauge is tucked inside the lower eyelid and removed after a minute to measure the moisture produced.

To investigate suspected infection on the surface of the eye, swabs will be taken from the affected area for laboratory analysis. Any bacteria or fungi present is identified and the appropriate antibiotics selected.

An ultrasound scan may be performed if it is not possible to see into the eye, or if a mass is suspected. For more in-depth investigation, it may be necessary to refer the horse to a specialist veterinary ophthalmologist.

What can a horse see?

A horse’s eyes are positioned on either side of his head. The resulting vision is largely monocular, meaning his brain receives different visual information from each eye to create an almost panoramic view. Although this helps a horse detect an approaching predator, he sees less detail than species such as humans.

A horse has two blind spots: one in front of him and one directly behind. Horses tend to be long-sighted, most likely due to their evolutionary adaptation as prey animals. Although it is generally accepted that they possess some form of colour vision, this appears to more closely resemble that of colour-blind humans.

Another piece of the puzzle

While assessing a horse’s vision remains relatively subjective, one of the more reliable methods is the maze test. This involves blindfolding each eye in turn and encouraging the horse to manoeuvre through an obstacle course of objects such as upturned buckets and hay bales, placed in random positions.

Struggling to negotiate the obstacles without knocking into them may reveal significant visual problems in one or both eyes.

Ref Horse & Hound; 5 November 2020

Ria Chalder MRCVS looks at some of the most common eye problems found in horses.

1. Eyelid laceration

Eyelid lacerations occur relatively frequently in horses when they catch their eyelid on a sharp object in the stable after rapidly lifting their head in response to a noise or perceived threat. Your vet will usually need to sedate the horse in order to determine the extent of the damage to the eyelid and the best way to repair it. Many horses that lacerate their eyelid will also have damaged the surface of their eye in the process (a corneal ulcer), so your vet may stain the surface of the eye with fluorescein dye, too.

How is it treated?

Eyelid lacerations should be regarded as an emergency and your vet called as soon as possible, so repair can be attempted before the damaged tissue begins to dry out and lose its blood supply. Many can be repaired with sutures (stitches) in the standing, sedated horse, but referral to a hospital for repair under general anesthesia may be required if there is extensive damage.

2. Eye problems in horses: immune-mediated keratitis (IMMK)

IMMK it is thought to be an immune-mediated disease whereby the horse’s own immune system attacks the surface of the eye. IMMK is not usually very painful, so signs can be subtle. Often a slightly cloudy white patch on the surface of the eye (referred to by vets as a “corneal opacity”) may be the only thing noticed at first.

A diagnosis of IMMK is made by ruling out alternative causes. Your vet may want to take some samples from the cloudy patch on the surface of the eye to rule out an infectious cause, such as bacteria or fungi, and to see what types of cells are present. Following this, a treatment trial of an immunosuppressive eye drop or ointment may be recommended in order to see if the eye responds to the treatment. Once a diagnosis of IMMK has been made, the disease can be further categorised into four types, based on how deep the disease is in the cornea. The four types are (in order of increasing depth): epithelial, superficial stromal, mid-stromal and endothelial IMMK. A piece of equipment called a slit lamp is usually required to determine the depth of the disease.

How is it treated?

Treatment will usually differ depending on the depth of the disease. Initial treatment usually consists of eye drops that suppress the immune response. This may be in the form of corticosteroids (steroids) or cyclosporine. Ruling out infectious causes prior to treatment is important as steroids should not be used if an infection is present.

In deeper stages of the disease, steroid injections in the tissue surrounding the eye, in addition to drops or ointment, may be used together. If the condition does not respond to topical treatment or a resistance to treatment develops over time, your vet may advise a surgical procedure called a superficial keratectomy, whereby the abnormal tissue is removed from the surface of the eye.

More recently, slow-release cyclosporine implants similar to those used in horses with ERU have been used in some cases of IMMK to remove the need for daily application of topical treatment. If left untreated, repeated episodes of IMMK can lead to the development of a scar on the surface of the eye.

3. Equine recurrent uveitis (ERU)

Equine recurrent uveitis (ERU) is a devastating autoimmune syndrome which causes inflammation inside the eye (uveitis), eventually causing blindness in approximately half of all horses affected. Research suggests that there may be a genetic component to the disease as it is seen more commonly in certain breeds such as Appaloosas and warmbloods. Environmental factors, injury and certain infections may also contribute.

ERU is diagnosed when there is inflammation seen within the eye, usually combined with pain and a history of similar episodes. There are three different types of ERU — the most common, “classic” ERU, is characterised by recurrent episodes of severe eye pain (squinting, tearing) and inflammation inside the eye lasting two to three weeks. “Insidious” ERU is typically less painful than the classic form, but low-grade inflammation still damages the internal structures of the eye over time.

Due to the more subtle signs, a diagnosis may only be reached quite late in the disease. “Posterior” ERU is least common. The inflammation and damage is in the back (posterior) of the eye, so can go unnoticed for some time.

How is it treated?

There is no cure, and treatment is aimed at reducing the frequency and severity of flare-ups. It usually involves anti-inflammatory medication in the form of immunosuppressive eye drops and oral anti-inflammatory medication, such as flunixin or phenylbutazone (bute). Atropine drops may also be used to help treat the pain and to open (dilate) the pupil. It is crucial that treatment is continued for several weeks, because the inflammation in the eye remains for a long time, even once clinical signs have resolved.

Stopping medication too early will likely result in another flare-up in the near future. If medical treatment is unsuccessful, there are a number of alternative options. For example, a small silicone device that slowly releases an immunosuppressive drug called cyclosporine can be implanted into the space surrounding the eye. The implants release the drug for up to five years.

Minimising potential triggers is important when managing horses with 
ERU — for example, decreasing UV and wind exposure. However, even with aggressive treatment, affected horses can go blind in a matter of years. Early involvement of a specialist veterinary ophthalmologist maximises the chances of managing the disease and prolonging the horse’s sight.

4. Eye problems in horses: corneal ulcers

Corneal ulcers occur when the surface of the eye (the cornea) is damaged. The prominent position of the horse’s eyes makes them more prone to injury, so corneal ulcers are a relatively common occurrence. They can be very painful, and horses with a corneal ulcer will often be found with their eye streaming and clamped shut. If your vet suspects a corneal ulcer, they will apply an orange dye called fluorescein to the surface of the eye. The stain will stick to damaged cornea only, highlighting the location and extent of any ulcer present.

How are they treated?

Most ulcers are simple scratches that heal quickly with appropriate treatment, which usually includes antibiotic drops to prevent infection while the ulcer heals. However, if an ulcer becomes infected with bacteria or fungi, it can take longer to heal. Inappropriate use of antibiotics over the past few decades has led to the emergence of multi drug-resistant strains of bacteria. For this reason, your vet may want to take a swab of the ulcer to determine which bug is growing and which antibiotic drop will be most effective against it. A medication called atropine may also be used which can relieve painful muscle spasm.

Some ulcers are slow to heal and may need the unhealthy tissue removing (debriding) with a cotton bud or a piece of equipment called a diamond burr. This is a relatively simple procedure, usually performed under sedation and with topical anaesthetic to numb the surface of the eye. Deep ulcers are considered an emergency and may require your horse to receive intensive around-the-clock medical treatment at a hospital, or even surgery to repair the damage.

• For unlimited access to our extensive online library of expert veterinary advice covering common equine aliments and conditions, subscribe to the Horse & Hound website

Found this useful? You might also enjoy reading these:

Equine eyesight questions answered, plus vets share advice on common vision problems to look out for

How to train, ride and manage a partially sighted horse: advice from owners with experience

All you need to know about the equine eye *H&H VIP*

Our new occasional series zooms in on the equine eye. Looking into this complex device can offer vital clues about

Equine recurrent uveitis (moon blindness) in horses

Find the perfect fly mask to keep your horse comfortable all summer long

Subscribe to Horse & Hound magazine today – and enjoy unlimited website access all year round

Stay in touch with all the news in the run-up to and throughout the major shows and events during 2026 and beyond with a Horse & Hound subscription. Subscribe today for all you need to know ahead of these major events, plus online reports on the action as it happens from our expert team of reporters and in-depth analysis in our special commemorative magazines. Have a subscription already? Set up your unlimited website access now

Guard against sore, scratched or sun-damaged eyes this summer, with advice from Ria Chalder MRCVS

Summer can play havoc with a horse’s eyes, with flies, UV light, pollen and dry vegetation all posing potential risks.

Houseflies (the small, black pest termed Musca domestica) are attracted to the tears produced by a horse’s eyes and can often be seen swarming around the face. As they feed and breed on sewage, animal dung and other waste products, they can transfer bacteria on to the eyes and cause an infection called bacterial conjunctivitis.

Often referred to as “fly eye”, bacterial conjunctivitis can make the eyes weepy and red – often with a greeny-yellow discharge. The condition is not particularly painful. A mild bout can usually be managed by bathing the eyes twice daily with cotton wool pads soaked in sterile saline, or salty water that has been boiled and left to cool. The eyes should then be covered with a good-quality fly mask to prevent re-infection.

If this fails to improve symptoms within a day or two, call your vet. Any sign that your horse is squinting, or that one or both eyes seem painful, should be treated as a veterinary emergency.

Never buy over-the-counter eye drops for humans to treat your horse if you suspect that he has bacterial conjunctivitis. Using antibiotic drops without veterinary supervision increases the likelihood of resistant “superbugs” developing, which can make treatment of subsequent, more serious infections difficult. It also complicates matters if the infection fails to resolve and diagnostic tests are required.

A correctly fitting mask that completely covers the eyes, in combination with a strong insect repellent, will go a long way to preventing bacterial conjunctivitis. Homemade fly repellents are rarely effective. Instead, try one containing at least 2% permethrin, or a synthetic pyrethroid such as cypermethrin.

Light relief

In humans, long-term exposure to excessive amounts of UV light from the sun has been linked to damage to the retina, at the back of the eye, and the formation of cataracts. These abnormalities tend to develop after decades; since horses have a shorter lifespan, UV-induced damage inside the eye is less of a concern.

Even so, these invisible rays have a lot to answer for when it comes to equine eye problems.

UV light is partly responsible for a type of cancer called ocular squamous cell carcinoma (SCC). Tumours can develop in several locations on or around the eye, including the skin, the membrane that lines the inside of the eyelids (the conjunctiva), the third eyelid and the clear cornea at the front.

The tumours are usually pink, raised nodules with a rough appearance and tend to cause a thick, whitish-yellow eye discharge. Fortunately, this type of tumour does not tend to spread internally, but it can invade important structures in the area.

Horses with pink skin around their eyes are at greater risk of developing ocular SCC, as are certain breeds including Belgian Draughts and Haflingers. If your vet suspects that your horse has an ocular SCC, it may be necessary to take a sample of the tissue, known as a biopsy, which can be sent for analysis to confirm the diagnosis.

Treatment options depend on the location and/or size of the tumour. Removal of the tumour is recommended, in combination with an additional treatment such as chemotherapy (in the form of creams and injectables), radiation therapy, photodynamic therapy or freezing (cryotherapy).

Tumours can recur, however, after treatment. Researchers in America found that the only factor associated with a decreased risk of ocular SCC recurrence was the use of a fly mask with 90% or more UV light protection.

Although not proven, UV light also appears to trigger flare-ups of equine recurrent uveitis (ERU) – a condition that causes recurrent bouts of painful inflammation inside the eye and is the leading cause of blindness. While ERU is still poorly understood, owners of affected horses will testify that the sun and wind are major contributing factors to an episode of this devastating disease.

Again, it is advisable to use a fly mask that also blocks harmful UV rays. Sun visors are now available for use while the horse is being ridden, offering 100% UV protection.

Itch and scratch

Warmer, drier weather will also see an increase in the occurrence of corneal ulcers, the term for scratches on the surface of the eye. As trees and bushes become dry and spiky, a horse’s prominently positioned eyes are vulnerable to scratches as he grazes.

The problem is usually obvious, as the pain will cause your horse to squint and the eye to water. And the offending piece of twig or thorn may still be seen embedded in the surface of the eye.

A corneal ulcer requires immediate veterinary attention. Your vet will most likely stain the surface of the eye with a green dye called fluorescein to determine the size and depth of the ulcer. Prompt treatment, including pain relief and frequent application of antibiotic eye drops, is then essential to prevent sight-threatening infection.

Itchy eyes, also common during spring and summer, can be a sign of an allergic reaction such as allergic conjunctivitis. The eyes will tend to be puffy, the conjunctiva bright pink and the eyes slightly watery.

Treatment is similar to that of hay fever in humans: avoid the trigger. If your horse’s signs worsen when the pollen count is high, for example, try to keep him stabled during the day.

Although it may seem a relatively trivial disease, it is important to address allergic conjunctivitis with the help of your vet. A horse may try to rub his itchy eyes against sharp edges, potentially injuring himself. If they are so itchy that the horse is self-traumatising the eye area, your vet may administer strong anti-inflammatory medications to provide immediate relief.

While antihistamines are also commonly used to help relieve the clinical signs of allergies, their efficacy in horses is not well understood. They appear to work best as a preventative measure before the beginning of the allergy season, rather than once a horse is itchy. If he is affected this summer, it’s worth planning ahead next year.

Choosing and using protective fly masks

Fly fringes are relatively ineffective and do not provide any UV protection, so are best avoided. Instead, opt for a mesh fly mask that covers the eyes – this will not only keep bugs away, but will shield the eyes from sharp objects and foreign bodies while he grazes.

Invest in a quality mask with high UV protection properties, taking care to:

● Make sure it fits. Too loose and the mask will allow flies to crawl underneath it; too tight and it will chafe the skin. An ill-fitting mask may even rub the eyelashes or push them on to the surface of the eye, causing serious injury. A good design will feature several darts around the eye area, to ensure that

the mesh sits well clear. Additional features may include adjustable fastenings and soft padding at the brow and around the nose for comfort.

● Keep it clean. A dirty mask will shed dust into a horse’s eyes and

can make problems worse, so shake the mask out each time it is fitted and clean it regularly. A machine-washable version will make this easier.

● Check it frequently. Even if you are not riding your horse, take the mask off at least once a day to check his eyes and to ensure that he is not being rubbed.

Ref Horse & Hound; 11 June 2020

You may also be interested in…

Equine recurrent uveitis (moon blindness) in horses

All you need to know about the equine eye *H&H VIP*

Our new occasional series zooms in on the equine eye. Looking into this complex device can offer vital clues about

7 famous one-eyed horses who have excelled in their careers

Most older horses have eye problems — but owners are unaware

‘Owner recognition of disease is important as they are the persons responsible for presenting animals for veterinary care’

Tackling eye tumours: what are the latest treatment options? [H&H VIP]

Eye tumours and cysts are some of the most common equine ophthalmic problems. Philip Ivens MRCVS reveals how pioneering methods

• This article has been edited and approved by Karen Coumbe MRCVS, H&H’s veterinary advisor since 1991.

Uveitis means inflammation within the eye. It should only be termed equine recurrent uveitis when two or more episodes occur. It is a complex condition, which is the most common cause of blindness in the horse worldwide and a very common cause of chronic eye pain in horses. Patient outcomes are improved by early diagnosis, appropriate therapy and clear understanding of the disease. Recent advances in treatment have helped.

The condition was historically called moon blindness, as when the cause was unknown, the intermittent nature of the disease was suggested to be associated with the phases of the moon. We now know that recurrent equine uveitis is a recurring immune-mediated inflammation of the equine eye, which after a lifetime of inflammatory episodes is not surprisingly more common in older horses.

ERU is fairly rare in the UK, with around half of those horses that have had uveitis suffering a recurring problem.

ERU is more commonly seen in the USA and in central Europe, particularly in Germany and the Czech Republic. Much of the research into treatments of the disease has been carried out in these countries.

It usually occurs in horses who are more than four years old and often becomes a noticeable problem in mid-adult prime performance years. The disease just affects one eye in about 50% of horse, except for the Appaloosa breed, which has 80-87% bilateral uveitis.

Equine recurrent uveitis [1,021 words]: Signs | Treatment | Causes | Risks | Prognosis | Prevention

Signs of equine recurrent uveitis

The clinical signs are highly variable depending on how chronic the condition is with many early cases showing relatively subtle signs of intermittent squinting, tearing or cloudiness in the eye, which may be dismissed as minor.In time these may progress to include a partially closed, inflamed eye with a watery discharge. Usually the eyelids will close over the painful eyeball, but if the eye can be seen, it may look cloudy with a constricted pupil. The horse will be sensitive to bright light and feel more comfortable in a dark stable.Summary of signs to look out for include:

• Swollen eyelids
• Sensitivity to light = keeping the eye closed
• A cloudy cornea
• Colour changes in the iris
• A constricted pupil
• Material within the front chamber of the eye such as blood, fibrin or pus
• Reddening around the eye
• A yellow-green discolouration deep within the eye
• Pain, which shows as eye closure and increased tearing

Treatment of equine recurrent uveitis

With any signs of an eye problem, a vet’s advice should be sought urgently. With uveitis cases rapid, aggressive treatment is required to reduce the likelihood of the horse losing the sight in the eye and reduce the pain of the condition.

The most critical component of the treatment is anti-inflammatory therapy, using medication, such as corticosteroids. These can be administered using drops or as an injection of a slow-release compound under the lining of the eyelids. In addition, an injection of corticosteroids can be given to deliver the medicine via the horse’s bloodstream. Complications can ensue if the painful eye develops a corneal ulcer, in which case steroid treatment will make it worse. For this reason, empirical treatment should never be started without checking with your vet first.

When there is corneal ulceration present, other treatment options are required, including non-steroidal inflammatory medication. In all cases, it is important to give appropriate medication for pain relief and to reduce the spasm within the eye that is causing the pupil to constrict, as well protecting the delicate corneal surface of the eye.

In Britain, we rely heavily on medical therapy whereas in other countries where the disease is more common and may have a different pattern of causes, surgery in the form of vitrectomy (removing the vitreous fluid from behind the lens), has a good record of preventing recurrence of the disease, but how successful it is at preserving vision is uncertain.

Recent treatment innovations have become available that work on immunosuppressing the affected eye, using local implants of the immunosuppressive medication cyclosporine. This is used to help horses with the disease that cannot be managed with topical ointments, drops and other medication, particularly steroids.

Another fairly new and not yet validated approach is injecting low dose of gentamycin or other medication directly into the eye. This can be performed with standing sedation and appropriate sterile preparation, but it not without risk.

If the condition does not improve, the horse can be left with a permanently painful and unsightly eye. In these cases removing the eye completely is the best way forward, even in an older horse. This can be done in the standing, sedated horse using local nerve blocks and is relatively straightforward. This removes the source of discomfort and many one-eyed horses can return to full work, including jumping.

Causes of equine recurrent uveitis

The cause of the disease is both unclear and complex. Some cases of simple uveitis can be linked to an identifiable cause, such as blunt trauma, corneal infection or a disease that damages the eyeball. When there is no history of external trauma or injury to the eye, it is most likely to be an autoimmune type of disease: essentially, a disease caused by the horse’s immune system ‘attacking’ itself.

Any inflammation of the structures within the eye can lead to severe and permanent damage to its function of providing sight. In horses with equine recurrent uveitis it appears that the eye has lost this immune privilege, which results in it giving a more generalised inflammatory response and subsequent permanent damage to the eye.

In both Germany and the USA specific types of bacteria known as Leptospira species appear to be implicated. A recent study¹ suggests that Leptospira does indeed cause some cases of uveitis in the UK, however this number is small compared to some other parts of the world.

Which horses are most at risk?

Appaloosa and Appaloosa-derived breeds appear to be susceptible to the disease, with clinical cases in these horses proving very difficult to manage. In addition, there is familial history of ERU in some breeding lines of other breeds.

Prognosis

A US study² found almost 30% of horses with ERU were blind in the affected eye by the time they were first seen by a vet. Around 30% of horses with uveitis had to be retired due to the condition, and another 30% performed at a reduced level than before the disease started. 15% of horses were put down due to bilateral blindness or chronic, uncontrollable pain.

How to prevent equine recurrent uveitis

Prevention is difficult as the trigger factors are not clearly understood. It is important to contact your vet promptly if your horse has a painful eye, rather than reaching for a tube of ‘eye cream’, since some treatments may make the condition worse.

It is advisable to avoid breeding from affected horses, since genetic selection of individuals free of the disease may reduce its prevalence in the future.

Owners often underestimate the severity of any visual defects, with little idea what their horse can or cannot see. Older horses often have a standard routine, rather like many older people, mostly in familiar surroundings with the same companions and few changes in their environment. This means these horses can cope with deterioration to their vision without people noticing.

Recent research³ confirms that vets detect many more problems in older horses’ eyes than their owners/handlers knew were there. It therefore makes sense to have older horse’s eyes checked, possibly as part of a regular health check, so that any problems can be detected early.

References

1: https://onlinelibrary.wiley.com/doi/full/10.1111/eve.12878 – Does leptospirosis cause uveitis in the UK? – December 2017

2: https://www.ncbi.nlm.nih.gov/pubmed/25891653 – Prognosis and impact of equine recurrent uveitis – May 2016

3: https://www.ncbi.nlm.nih.gov/pubmed/30080275 – Prevalence of owner-reported ocular problems and veterinary ocular findings in a population of horses aged ≥15 years – August 2018

Also: https://onlinelibrary.wiley.com/doi/full/10.1111/eve.12548 – Equine recurrent uveitis: A review of clinical assessment and management – February 2016

• For unlimited access to advice on how best to care for your horse, subscribe to the Horse & Hound website

You may also enjoy:

Equine eyesight questions answered, plus vets share advice on common vision problems to look out for

Why do horses wear sunglasses?

7 famous one-eyed horses who have excelled in their careers

‘It was absolutely terrifying’: owner shares uveitis experience that nearly took her horse’s life

17hh gelding Chance was first diagnosed with the disease last July

Understanding equine eye problem uveitis *H&H VIP*

What makes the body’s immune system turn on itself, causing devastation to the internal structures of the eye? Dr Andy

Subscribe to Horse & Hound magazine today – and enjoy unlimited website access all year round

Horses cope surprisingly well with limited vision. They are not required to read or write, after all — their eyes are essentially designed to spot food, water and predators. Yet we’ve redesigned their roles, so they need to watch out for cross county fences, showjumps, arena edges and other obstacles.

Older horses often have a standard routine, rather like many older people, involving familiar surroundings, the same companions and few changes in their environment. This means that they tend to cope with deterioration to their vision without anyone noticing. Owners typically underestimate the severity of any visual defects and none of us really know what a horse can or cannot see.

Common problems

Horses do suffer from age-associated vision changes, but rarely to the point of blindness. Even so, it is important to be aware of the potential problems and the associated human safety and horse welfare implications.

• The cornea — the clear “window” at the front of the eye — is vulnerable to injury at all ages, largely due to the prominent position of the eyes on the side of the head.Corneal disease is common and has the potential to be more serious in older horses. With time, changes can affect the ocular (eye) surface and cause deterioration in the tear film — the natural lubricant covering the eye. Tear deficiency and dry eye syndromes are rare in horses but are more likely with increasing age.Older animals tend to develop corneal ulcers that are slow to heal, often near the lower eyelid. They may also be more prone to ulcers in the first place. There are suggestions of a reduction in corneal sensitivity, particularly with pituitary pars intermedia dysfunction (PPID, otherwise known as Cushing’s disease) sufferers, which can leave the eye more vulnerable to injury.● Uveitis — inflammation within the eye — is reported to some degree in many older horses’ eyes upon ophthalmic examination. Before the cause was known, the intermittent nature of the disease was thought to be associated with the phases of the moon, hence its historical name “moon blindness”.We now know that uveitis is linked to the immune system. After a lifetime of inflammatory episodes, the condition can be more problematic in older horses. Recent treatment innovations, such as local implants with the immunosuppressive medication cyclosporine, may help cases that cannot be managed with topical ointments, drops or other medication.When an affected eye remains painful and unresponsive to treatment, removal remains the best option — even in an older horse. This can be done in the standing, sedated horse using local nerve blocks and is relatively straightforward.● Glaucoma causes increased accumulation of fluid, raised pressures and swelling within the eye, usually occurring as a complication of equine recurrent uveitis. Recent studies reported that 65% of equine glaucoma cases presented in horses older than 15 years, so seek veterinary advice if your veteran develops a bulging eye.● Cataracts are defined as an opacity in the lens within the eye. Senile cataracts can appear as the lens loses transparency with age, although horses often cope remarkably well, provided there is not a complete cataract that covers the lens. The lens also become less flexible with age; while spectacles will help humans, this is not an option for our equine patients.Cataract surgery can correct significant visual impairment but should only be considered if there are no other concurrent eye conditions. Many cataracts are a complication of underlying inflammatory eye disease, so simply removing the cataract is unlikely to help if the eye is already damaged. It is also questionable whether it is the right thing to do in an older horse.● The retina, at the rear of the eye, registers the image that the horse sees. Unfortunately, the retina deteriorates with age and treatment options are limited.Studies on horses aged over 30 years revealed senile retinopathy (age-related damage) in nearly three quarters of them. It is unclear, however, how much the condition affects vision.

On the blink

Accurate visual assessment of any horse is surprisingly difficult. We still do not know exactly how much a healthy young horse can see, let alone an older animal with detectable visual problems.

A vet may use an obstacle test, blindfolding one of the horse’s eyes and then the other, as well as a full clinical examination. Physical examination may show cloudiness, discolouration or distortion in the shape of the eye.

The so-called menace response, which tests whether a horse blinks at an approaching hand, can be hard to interpret accurately as many horses blink in response to the resulting air movement. It is sometimes best to stand back and observe the horse’s behaviour pattern over time.

The relatively delicate skin around the eye should also be monitored, along with the pink conjunctival membranes in the eye socket that are especially sensitive in appaloosas and cream or coloured horses as they age. These are prone to irritation from dirt, dust and sunlight, among other things, and may benefit from protection offered by a well-fitting eye or fly mask.

Tumours such as squamous cell carcinomas, melanomas or sarcoids can appear around the eye. The key message with any lump or bump is to catch it early and seek veterinary advice — removal is simpler when the mass is small, especially if the eyelid is involved.

Many ophthalmic conditions are progressive and, given time, will begin to surface as your horse becomes a veteran. If you don’t look, you won’t find them, so it’s wise to arrange regular eye checks. Not all will cause problems, but it is always best to know so that the condition can be monitored and, if possible, treated.

The signs

Vision loss is often gradual and may go undetected. Ask yourself these questions and call your vet if you sense that something is amiss.

Is your horse losing confidence? Look for subtle changes — he may become uncertain in his gait, especially in dim light, or reluctant to walk over unfamiliar ground. He might bump into walls or fences, perhaps misjudging the width of a stable door and knocking himself.

Has he become bolshy or unpredictable? Walking over or barging into a handler could indicate altered vision. A horse will be more prone to accidents and injury if he is unable to assess hazards.

Is he less certain in the field? Be aware of behavioural or pecking order changes, especially among established herds. A horse with poor vision may follow others closely, tilting his head and using his ears as he relies on his hearing.

When ridden, is he unusually awkward? If his vision is changing, he may shy frequently and become less responsive to the aids or more reluctant to move forwards.

Is he ‘nosier’? He may start using touch, running his nose over novel objects — a good reason not to trim whiskers and eye feelers, as they provide vital sensory feedback.

Any noticeable signs? An eye that appears painful and is partially closed, or has obvious discharge or discolouration, needs veterinary attention.

Ref Horse & Hound; 11 April 2019

A horse who faced being put down after a tumour was found in his eye has a won championship title after the affected eye was removed.

Kate O’Shea from Cork and her 16.2hh part-bred Connemara Send Me On (Hudson) won the advanced intermediate championship at the national hunter trials championships at Annaharvey Farm in Co. Offaly, Republic of Ireland on 31 March.

Kate beat 30 other riders to take the title, with three seconds separating the top three combinations.

“Cross-country is his favourite,” Kate told H&H. “We mostly event during the summer but our season hasn’t started yet so we’ve been doing hunter trials.”

Kate, who has owned Hudson for five years, said his eye became cloudy at the beginning of 2016.

“We got the vet who originally thought he’d been pricked by a thorn or something out hunting so he diagnosed an infection of the cornea and we were treating that for two weeks,” she said.

“The vet came back again and gave us strong drops to try but when he didn’t improve he wanted a second opinion.”

Hudson was seen by a specialist who diagnosed a melanoma tumour in his left eye.

“They ultrasounded his eye and found a tumour growing rapidly against his cornea and said his eye would have to be removed.

“We were obviously very upset and had to decide what to do. People had different opinions about whether we should go ahead with surgery and take his eye out, or put him to sleep.

“My family are very into horses and my aunt used to work in a racing yard and knew two horses with one eye – one didn’t cope. He became very nervous and anxious and lost weight rapidly, it just stressed him out so much. No one wanted to put Hudson down but we had to consider what was best for him and whether he would cope with one eye.”

Kate went ahead with the surgery on 23 January 2016.

“Hudson is a kind horse and our vet said he had the right temperament and there shouldn’t be problems in him having one eye. He knew plenty of horses who were very successful with one missing, so we went ahead with the operation and hoped for the best.

“We collected him from the vets two days later and he travelled home perfectly.”

Kate said Hudson adapted well to having one eye and soon returned to hunting.

“He was on box rest for two weeks and had his stitches out on 5 February. I got on him the following day and walked around the arena – my mum was more nervous than me, I just couldn’t wait to get back on and he was absolutely perfect,” she said.

“We went out hunting a week later and he was leading the other horses over ditches.”

Elite showjumper returns to top level after losing an eye

The 16-year-old stallion has made a successful return to the highest level of the sport following an operation to remove

The one-eyed team-chasing former racehorse who ‘never says no’

The racehorse was being aimed at the Grand National when a freak accident ended his first career

Subscribe to Horse & Hound magazine today – and enjoy unlimited website access all year round

Kate said she does not mind what Hudson looks like and that people do not notice he only has one eye.

“I had seen horses with one eye like Adventure De Kannan the Hickstead derby winner, and there’s an event horse in Ireland called Wysteria Lane, so you see them out competing. The vet did a really good job, a lot of people don’t even notice until you point it out to them.

“His behaviour is exceptional. He’ll be eager pulling me round cross-country, but then my mum can also get on him and he’ll walk up the road slowly for her – he’s so safe. He’s just brilliant.”

For all the latest news analysis, competition reports, interviews, features and much more, don’t miss Horse & Hound magazine, on sale every Thursday.

Stay in touch with all the news in the run-up to and throughout the major shows and events during 2026 and beyond with a Horse & Hound subscription. Subscribe today for all you need to know ahead of these major events, plus online reports on the action as it happens from our expert team of reporters and in-depth analysis in our special commemorative magazines. Have a subscription already? Set up your unlimited website access now

A top showjumping stallion has returned to the sport at the highest level after having an eye removed.

Cornado NRW injured the eye at the end of 2018. However it didn’t heal, so the decision was made to remove it.

The 16-year-old has been competing on the international circuit since 2011 and is one of German showjumper Marcus Ehning’s elite string.

“He has adjusted very well and Marcus is very happy to have him at the competitions again,” Judith Gölkel from the Sportpferde Ehning team told H&H.

“He jumped fantastic in s-Hertogenbosch and the plan is to take him to Paris this weekend.”

A video of Cornado jumping a beautiful clear at the Indoor Masters in ’s-Hertogenbosch on 15 March has been viewed more than 25,000 times.

“Cornado has shown himself from his best side today,” said the team.

“We are happy that he survived his eye removal so well and are overjoyed to have him back at tournaments.”

Cornado last jumped in front of a crowd at Spruce Meadows CSI5* in September. He was entered for the Nations Cup final in Barcelona in October, but was withdrawn before the start.

The striking grey, by Cornet Obolensky, was Marcus’s ride at 2014 World Equestrian Games in Normandy, where he helped Germany to team fourth place as a team and finished 10th in the individual.

Article continues below…

You might also be interested in:

7 famous one-eyed horses who have excelled in their careers

Subscribe to Horse & Hound magazine today – and enjoy unlimited website access all year round

Vets use bra to save miniature pony’s eye

The C-cup is being used to treat a corneal ulcer in the right eye of the miniature pony

He has twice finished fourth at the FEI World Cup final (2014 and 2016) and was 12th at last year’s event in Paris.

His glittering intercontinental career includes CSI5* grands prix wins at Verona (2013), Bordeaux (2014), Paris (2014) and ‘s’Hetogenbosch (2016), plus numerous top placings and a win at the 2013 CSI3* Herning grand prix in Denmark.

For all the latest news analysis, competition reports, interviews, features and much more, don’t miss Horse & Hound magazine, on sale every Thursday

Stay in touch with all the news in the run-up to and throughout the major shows and events during 2026 and beyond with a Horse & Hound subscription. Subscribe today for all you need to know ahead of these major events, plus online reports on the action as it happens from our expert team of reporters and in-depth analysis in our special commemorative magazines. Have a subscription already? Set up your unlimited website access now

A blind horse has proved that a total loss of eyesight doesn’t have to be a barrier to success. Elizabeth Shorthouse’s Norwegian Fjord Ausdan Warrior (Rio) lost his sight in both eyes in 2016, but recently made a return to the dressage arena at Swallowfield Equestrian Centre, Warks, scoring 63.7% in an intro test.

“In November 2016 I noticed there was something wrong almost overnight — he was coming into his stable and couldn’t seem to find his haynet or his food,” Elizabeth told H&H.

“He was seen by a specialist who told us he had uveitis and there was no blood supply to one eye, and the retina was detaching in the other, and he would have no sight. I was sobbing my heart out but the specialist told me to go out and show the world what a blind horse can do, and that’s what we’ve done.”

Elizabeth, who has owned the 10-year-old grey dun since he was a foal, started riding Rio again three weeks after the diagnosis, starting in walk. The pair had “dabbled” in dressage previously and finally took the plunge to enter an unaffiliated class.

“We can’t go in the show ring any more as there’s too much hustle and bustle, but the set pattern of a dressage test gives him confidence. I ride around the arena first, going right into the corners, and he forms a map in his head,” said Elizabeth, who has taught Rio to respond to the commands ‘step up’ and ‘step down’, which has helped him load and travel in the lorry, and to stop if she says ‘wall or ‘gate’.

“We have such a bond. He trusts me and really tunes into everything I do,” she added. “I have to be very aware of my body and my head because he will respond to my movement. He used to hear things and get distracted, but he’s very relaxed now. He just loves to work and always tries his best, and he knows I wouldn’t put him in a bad situation.

“I wore high-viz with the words ‘caution – blind horse’ in the warm-up arena at Swallowfield, but he’s used to being ridden with the horses at home and he was fine.”

Continued below…

Meet Digby, the UK’s first guide horse

Digby will be assisting Blackburn-based Mohammed Salim Patel

How a registered blind rider found her dream horse

Finding your dream horse can be a daunting challenge for any rider. But what about if you are registered as

Partially blind horse shot 130 times with paintballs

The underweight, elderly mare with no identification is blind in her right eye

Elizabeth hopes that Rio — who she believes is the only totally blind horse competing in dressage in the UK — will inspire other riders of partially sighted or blind horses not to give up on them.

“I want to show that this is an obstacle, but not a barrier. When Rio was first diagnosed people asked if I was doing the right thing by riding him, but I’m so glad I didn’t write him off. At home I treat him as thought he’s not blind and he loved being out competing.

“There’s no stopping us now — we’re aiming to do MyQuest, and to get to the British Dressage Draught Horse Championships.”

For all the latest news analysis, competition reports, interviews, features and much more, don’t miss Horse & Hound magazine, on sale every Thursday.

This latest edition (31 May) is a training special, including a look at the world’s top trainers and whether you should have multiple coaches. Also check out our summer clothing guide, interview with showjumper and recent winner of the Hamburg Derby, Matt Sampson and feature on health problems in miniature horses

Stay in touch with all the news in the run-up to and throughout the major shows and events during 2026 and beyond with a Horse & Hound subscription. Subscribe today for all you need to know ahead of these major events, plus online reports on the action as it happens from our expert team of reporters and in-depth analysis in our special commemorative magazines. Have a subscription already? Set up your unlimited website access now

Five weeks ago, Suzy Feltham thought she had lost her beloved coloured show horse, Star Dream, for good after going through one of the worst winters of her life.

‘Dexter’, a 16.1hh coloured gelding, suffered a hairline fracture in his pelvis in October. Then after being on box rest until January, he developed an ulcer in his eye.

“It was honestly such a hard winter,” said Suzy. “After several operations on the ulcer, me and the amazing vets at the Royal Veterinary College made the decision to have his eye removed. There was nothing else we could do.

“To make things worse, he then developed a serious infection — I thought I was going to lose him.”

Dexter’s eye was removed eight weeks ago leaving him with just a socket on one side of his face. He’s been discharged from the veterinary hospital for just five weeks.

“I didn’t think we’d be able to come,” she added. “He loves to be out and about, so when he was recovering well, I decided to bring him.”

Dexter, who was placed sixth under-saddle at the Royal International last term with Georgia Aungier, made a fighting return to the show ring to stand third in a strong non-native horse in-hand class.

“The judge didn’t even notice his eye, and also commented on how well he looked and moved for his age. For me, I’m just delighted to have been able to get him out after his awful winter — he’s been on box rest for a total of eight months.”

At home, the incredible coloured is back out in the field enjoying life, and will be returning to competition under-saddle at the end of the month at Surrey County.

“I never thought we’d make it to Windsor — but he absolutely loved being able to show off again.”

Don’t miss next week’s issue of Horse & Hound magazine (17 May 2018) for full reports and coverage from the Royal Windsor Horse Show

For all the latest equestrian news and reports, don’t miss Horse & Hound magazine, out every Thursday.

Stay in touch with all the news in the run-up to and throughout the major shows and events during 2026 and beyond with a Horse & Hound subscription. Subscribe today for all you need to know ahead of these major events, plus online reports on the action as it happens from our expert team of reporters and in-depth analysis in our special commemorative magazines. Have a subscription already? Set up your unlimited website access now

When you look into your horse’s eyes, the parts you’ll notice are the light-transmitting structures — the cornea, the aqueous humour (fluid) within the anterior chamber, the lens and the gel-like “vitreous”.

In the horse, as in all mammals, this area is optically clear under normal circumstances. This clarity is a sign of ocular health, also offering the advantage that a vet can see deep into the eye using specialist instruments such as the direct ophthalmoscope.

It is possible to inspect these structures at the front of the eye, however, with little more than a small torch and cooperation from the horse.

Through the looking glass

The clear “window” into and out of the eye is called the cornea. This dome-shaped, transparent layer is an important component of the ocular focusing mechanism.

Although seemingly a simple structure, the cornea has a highly sophisticated and multi-layered anatomy that determines its optical clarity.

The healthy cornea is a relatively dehydrated structure, bathed in tears on the outside and aqueous humour on the inside. This dehydrated state is dependent upon the cellular pumps on its inner membrane, which force water out of the cornea and into the eye.

If these pumps fail, the cornea retains water and swells. The clear tissue becomes progressively opaque as its highly organised anatomy is disrupted, scattering transmitted light — rather like a sheet of clear Perspex becoming opaque along stress lines caused by bending.

These metabolic pumps are very sensitive to any injury or disease within the eye. Any opacity or greyness appearing in the cornea should prompt an owner to seek veterinary attention. Because the corneal surface is so richly supplied with nerve endings, it is one of the most sensitive structures in the body. Any surface injury will cause marked pain and an increase in tear production — another situation where immediate veterinary attention is called for.

The equine cornea appears to be susceptible to a range of diseases unique to the species, currently described using the generic term “immune-mediated keratitis”. In general, these conditions are not painful, and they typically appear as vague corneal opacities.

Causes are currently poorly understood and treatment can be challenging — and where successful, it is often lifelong. However, early recognition and treatment will increase the chances of successful control, at least, of the disease.

A lubricating layer

The thin sheet of tissue that covers the white “sclera” surrounding the cornea is called the conjunctiva. This folds around onto the inner surface of the eyelids, covering the third eyelid (the protective inner eyelid, also called the nictitating membrane).

The conjunctiva is a secretory membrane, supplying some of the important components of teardrops. It is vitally important in maintaining the health of the surface of the eye. Normally, it is a near-translucent structure, appearing slightly pink due to the underlying blood vessels. It can be heavily pigmented in some horses.

Inflammation (conjunctivitis), which in the horse is almost always secondary to some other problem in the eye, causes the conjunctiva to appear reddened and often swollen. Small tumours or growths of the conjunctiva are relatively common, particularly in eyes with little pigmentation. If caught early — which is critical — these can usually be dealt with by simple excision.

The horse’s pupil is shaped like a flattened sphere, corresponding to the visual horizon and assisting him, as a prey species, to scan this horizon continually for threats.

The dilated (open) pupil, on casual inspection, has a dark appearance. Shining a light directly along the visual axis, however, can result in a bright red/green pupil, as the light is reflected from a layer of tissue at the back of the eye called the tapetum lining. This is the reason why, at night, some animals’ eyes appear to “glow” in torchlight. Where cataracts of the lens are present, the pupil may have a pale appearance.

Pupil shape can change following injury inside the eye. Corneal pain will produce a narrow, slit-like pupil, as the muscles controlling pupil size go into spasm.

Pupil problems

The iris can be likened to the diaphragm of an old-fashioned optical camera, essentially controlling the amount of light entering the eye by altering the size of the pupil.

In most horses the iris is dark brown, but in lighter-coloured horses it may appear quite pale. In some pony breeds, or in black-coated horses, the iris can lack pigment, partially or totally. The resulting white, thin-looking appearance is often referred to as a wall eye.

These irises may also have gaps or windows in their structure, referred to as colobomas (picture, below). These have no deleterious consequences and may, in theory, permit a greater degree of depth perception in the eye. Where the iris joins the peripheral cornea, grey crescent-shaped lines may be seen. These “trabeculae” serve as drainage pathways, one of the routes through which aqueous humour leaves the eye. Clogging or collapse of this drainage angle, particularly following inflammatory disease inside the eye (uveitis), can be associated with glaucoma.

Dark-coloured, spherical structures may appear at the margin of the pupil. These are iris cysts, which arise from the inner surface of the iris and hang over its rim, attached by their umbilicus-like stalks. These are usually of no consequence, although very rarely they can grow and obstruct the pupil.

Inflammation of the iris (anterior uveitis) is usually part of a more generalised inflammatory process within the eye. When the disease is active, the iris can look muddy. The pupil is narrowed and the anterior chamber is filled with floating clumps or clouds of debris.

Affected eyes are typically very painful, but even in eyes with only minor discomfort, any cloudiness or debris within the anterior chamber is a potentially serious sign.

Iridology — the identification of more generalised disease-states from the appearance of the iris — is sometimes practised in horses. Despite having spent some 35 years studying equine eyes, this is a skill that lies well outside of both my understanding and my comfort zone.

Ref Horse & Hound; 25 August 2016

A C-cup bra is being used to save the eyesight of a miniature pony in New Zealand.

The pony called Little Jack is receiving treatment for a corneal ulcer in his right eye.

The team at the Veterinary Associates Equine Hospital in Karaka, a small town near Auckland have created a pump to get the antibiotics into the eye using a ladies bra.

Jack is also being given a blood serum manually to help the eye to heal.

The ulcer is the first major health scare for the tiny 17-year-old bay pony.

“He’s never seen a vet in his life, he’s quite a low maintenance little pony,” his owner Tanya Taylor told the local press.

Jack was her daughter Emily’s first pony and is now lent out for no charge for community events.

He is also used as a starter pony for Franklin Kidz Kartz for the races at Alexandra Park, home of the Auckland Trotting Club in Epsom.

Jack is popular with the children as he doesn’t take off with them. “They know they can have a safe ride on Jack,” Mrs Taylor said.

Mrs Taylor has started a Facebook page to raise funds to help pay for Jack’s costly treatment.

“There’s some very generous donations – I’m sure he’ll appreciate it,” she said.

Stay in touch with all the news in the run-up to and throughout the major shows and events during 2026 and beyond with a Horse & Hound subscription. Subscribe today for all you need to know ahead of these major events, plus online reports on the action as it happens from our expert team of reporters and in-depth analysis in our special commemorative magazines. Have a subscription already? Set up your unlimited website access now

Uveitis is a generic term used to describe inflammation of the blood vessels and vascular tissues within the eye.

In the horse, the disease can separately involve the front of the eye (when it is termed iridocyclitis) or the back of the eye (chorioretinitis), but in many cases the entire eye is affected to some extent.

The inflammation can arise from trauma or blood-borne infection, but in the horse the disease is most commonly endogenous — meaning there is no identifiable external cause. In these cases, evidence is mounting that the disease has an autoimmune origin.

This arises when the normally low-key immune responses within the eye — maintained that way to avoid triggering inflammation likely to damage the very sensitive and vision-critical structures — fail to recognise these ocular tissues as “self” and mount an aggressive response against them.

What causes this failure to recognise “self” is unknown, but it seems probable that in some cases, infection can initiate the disease by altering the immune signature of the eye tissues. The vigilance of the horse’s immune system does the rest.

Is bacteria to blame?

The infection currently receiving most attention as a likely cause of equine uveitis is leptospirosis.

In central Europe, where uveitis is reported to affect some 10% of horses, the Leptospira bacteria are implicated in up to 80% of cases. In the UK, the disease affects less than 0.2% of horses. The Leptospira types usually associated with the disease are absent from our wildlife population (the most important reservoir for infection), contributing to reduced incidence.

However, uveitis was once very common here in the UK and its prevalence among cavalry horses around the time of Waterloo was about 5%. Interestingly, in the mid-19th century a law was enacted in the UK preventing equines affected with the disease from entering horse shows, effectively removing these horses from the breeding pool. This may be largely responsible for the welcome decline in the disease over the past 150 years.

Recent studies have shown that there is a breed-related susceptibility to the disease, with warmbloods and appaloosa types being particularly affected. In the latter, the disease can take an insidious course, frequently grumbling along undetected.

However, it is highly likely that there are more and as yet unrecognised causes of uveitis in the horse, with each causal pathway leading to the same outwardly similar clinical presentation — inflammation within the eye.

A recurring problem

When it is recurrent, the disease is called equine recurrent uveitis. This is the common form in mainland Europe.

In the UK the disease is less commonly recurrent, which could reflect a genetic tendency within our horse population towards restoring the immune mechanisms in the eye to their normal low-key status after a single episode of the disease.

The structures within the eye are highly sensitive to injury or disease and have limited capacity to recover their original transparency or light-capturing functions.

Iridocyclitis, where the disease affects the front of the eye, is the most common presentation and is typically very painful. The horse’s eyelids may be tightly closed with evidence of marked tearing, while the cornea may appear opaque or reddened.

This is a real emergency in every sense. The earlier the diagnosis, the much greater the likelihood of successfully treating the disease — and the far lower the chance of long-term damage in the eye.

Unfortunately, the insidious disease seen in appaloosa types and the form of uveitis that affects only the back of the eye are not particularly painful, meaning these conditions often go undetected until the eye is irreversibly damaged.

Once the initial disease has settled down, the eye is left with signs of “healed” damage. These can range from being only detectable on biomicroscopic examination through to blind, internally scarred eyes with extensive cataracts present.

After the initial episode of acute disease, there is no reliable means of predicting its recurrence. If the disease is shown to be associated with Leptospira, which requires laboratory testing of samples of fluid taken from the eye, experience from continental Europe suggests recurrence is more likely. Similarly, where the disease initially affects only one eye, there is no means of predicting whether the opposite eye will be affected.

Experience in the UK indicates that if either event has not occurred within one year of the disease first appearing, then the chances of these events happening lessen significantly. However, lifelong vigilance for signs of recurrence is required.

Treatment challenges

Effectively treating the acute disease requires anti-inflammatory medication delivered directly on to the eye, in addition to anti-inflammatories and pain suppressants given by injection or in the horse’s feed.

Administering medication on to the eye is usually resented because of the pain, and failure effectively to medicate these cases is a common cause of what seems like treatment failure. For this reason, vets often fit a delivery tube through the eyelid to allow administration of medicines without going near the eye, and may hospitalise the horse for treatment by dedicated nursing staff.

Most eyes will get better with aggressive treatment, but some seem to respond temporarily or not at all. Frustratingly, that is the nature of this complex disease. In “healed” eyes, there is no means of removing the damage caused by the acute disease.

Recently, methods of surgically implanting medication delivery devices directly into eyes have evolved. These are used in recurrent disease to reduce the frequency and severity of episodes, in some cases eliminating them.

Where Leptospira is proven to be involved, surgically removing the vitreous gel from the back of the eye may help prevent recurrence — although most eyes will subsequently develop cataracts.

A blind eye, particularly where uveitis is recurrent, is best removed for the welfare of the horse.

Ref: Horse & Hound; 6 August 2015

The discovery of a cataract — typically during routine examination of the horse or at a pre-purchase exam (PPE, or vetting) — can be confusing and alarming for an owner.

Very broadly, a cataract is any opacity involving the lens of the eye. Cataracts vary widely in type and size, from small, single opacities present at birth to extensive and dense opacities obstructing the visual axis of the eye.

The condition can affect any type or age of horse and is common. A recent survey of racehorses in Australia found cataracts in 17% of the horses examined.

What causes cataracts?

The ocular lens is a highly complex structure made up of tightly and very precisely arranged transparent and metabolically active cells.

These cells are continually produced during the horse’s life and are required to remain alive and functional throughout, albeit the process slows with age. Biologically speaking, this is a huge ask of any tissue — it is remarkable that abnormalities of the lens are not more common.

Anything affecting the precise geometric laying down of lens cells during life, from the foetus to the adult, or interfering with the metabolic processes on which the transparency of these cells depends, will result in opacity and cataract.

In the horse, most cataracts result from the former and in some ways are similar to the types of cataract found in human babies and young adults. These cataracts tend not to enlarge over time.

Cataracts are less commonly caused by overt eye disease. This could be trauma or, very rarely, intraocular tumours. Most commonly, the cause is uveitis or intraocular inflammatory disease, a group of as yet incompletely understood diseases, including equine recurrent uveitis or periodic ophthalmia (so-called moon blindness). These cataracts can progress if the disease process cannot be effectively controlled.

Rarely, cataracts develop in adult horses for no apparent reason. Age-related or senile cataracts can be found in most horses over the age of 18, but appear to have little effect on their behaviour.

Weighing the evidence

Vision in horses is very difficult to assess objectively.

Horses appear able to interact with their immediate environment in a way which uses senses in addition to visual input, but which we forward-facing and vision-dependant primates assume to be primarily vision-based. This facility in horses is sometimes referred to as functional vision.

Most cataracts in horses do not appear to interfere with functional vision. Most affected horses behave normally, some competing at a high level. However, any cataract must, by default, interfere with the passage of light on to the light-sensitive photoreceptors of the retina. In turn, this must result in some degree of physiological disruption of normal eye function.

In fact, most horses seem to adapt to this readily, particularly where the cataract is present from early life — the exception being where a complete cataract, that is when the whole lens becomes opaque, occurs suddenly and usually as a consequence of uveitis.

The result of this is that attributing behavioural problems to cataracts in any one horse is a process fraught with subjective difficulties.

There is no medical treatment for cataracts. In selected instances, the opacity — in particular an extensive or total cataract — can be removed surgically and an artificial lens implanted. This surgery is not routine and is technically complex, expensive and involves aggressive aftercare, as well as carrying the risk of blinding.

Successful results have been achieved, particularly in foals and yearlings. Still, the long-term results are less promising. The most recently published results from two groups in the US record that overall only 25% and 48% of operated eyes remained “visual” after two years.

Ref: H&H 7 May, 2015

Is 20-20 vision a prerequisite for winners? Apparently not. On Sunday (29 June) Adventure De Kannan won the Hickstead Derby — with only one eye. The gelding, who had his right eye removed last summer due to an infection, took the class ahead of his fullsighted opponents, proving that partial vision need not be an obstacle.

And that applies to riders too. British Showjumping (BS) now has 3 blind riders registered, and reports it is a “developing” field.

Visually impaired rider Karen Ward hit the headlines at Royal Windsor in May, where she was presented with a horse by her mentor Dame Emma Jane Brown. Karen competes at BS’s club membership level, 70cm-1m, with a lead rider shouting out directions. She says she only has “a little light recognition”.

“We have other visually impaired riders making queries,” said Rebecca Turner, BS para co-ordinator. “One man wants to use an earpiece [giving directions], rather than a lead rider, which could make it a more level playing field.”

Across the disciplines

Dressage is the more obvious route for visually impaired riders, as the only para discipline recognised by the FEI with an appropriate category. According to their classification by the International Blind Sports Association, they compete either at grade III (classif ed as totally blind, and wearing a blindfold) or grade IV (partially sighted).

Nicola Naylor (pictured right) had 40% vision in just one eye growing up, which degenerated to “a little light perception” by her 20s. She competed in JA classes as a child when she could see just “the rough outline of a jump one stride away”.

She later turned to eventing. “I had to memorise the courses and for cross-country I relied on people standing with large coloured rugs at key turns to guide me round,” she said. “I coped thanks to clever ponies who could change their stride at the last minute, but I learned how difficult it was to continue on horses, who are not as nimble and need more guidance from the rider.”

She returned to horses 3 years ago, aged 50, thanks to her horse-mad daughter. She now competes in para internationals as a grade III and has qualified for the nationals at medium.

She says “keeping straight is the hardest thing with no external point of reference”. And because she specialised in jumping when she could see, she cannot visualise a pirouette or piaffe. “I have to learn through feel and relying on my trainers [Daniel Watson and Alex Wyatt] to feed back when something is right, so I can register that,” she said.

Nicola has competed at both para and ablebodied competitions. But, as she learned aged 16, when it comes to judging fences at speed, any visual impairment can signal the end of a career.

Laura Collett’s sight affected by fall

Four-star eventer Laura Collett lost the sight in her right eye last summer as a result of a bad rotational fall (news, 11 July 2013). She dislocated her shoulder, dislodging a fat embolism that damaged the optic nerve. She has been working with sports vision optometrist Gavin Rebello, who assesses the Harlequins rugby team.

“Laura had major hurdles to overcome and it’s testament to her character that she has adapted so well,” said Gavin. “Two eyes help you judge height and distance — vital in eventing. Her peripheral vision is also limited, which gives other cues such as shadows. Finally, her one eye has to work so much harder, and fatigue causes mistakes.”

“It was very hard dealing with depth perception at fi rst,” said Laura, who can no longer drive an HGV. “I would think I’d seen a stride, but the fence would still be further away — and my left eye got very tired as my right eye had previously been the dominant one. But I’ve adjusted and it feels normal now.”

Gavin prescribed a contact lens to stop her working eye becoming fatigued, enabling her to “see things earlier and make decisions in time”.

“The working eye needs to hit peak performance, so we have tried to make it as efficient, accurate and flexible as possible,” he said. “It can take a very long time — if ever — to recover after losing one eye, but Laura has the right mindset and motivation.”

Laura’s in good company. Jockey Red Pollard also lost the sight in his right eye — and it didn’t stop him steering Seabiscuit to greatness.

This news story was first published in Horse & Hound magazine (3 July 2014)

Stay in touch with all the news in the run-up to and throughout the major shows and events during 2026 and beyond with a Horse & Hound subscription. Subscribe today for all you need to know ahead of these major events, plus online reports on the action as it happens from our expert team of reporters and in-depth analysis in our special commemorative magazines. Have a subscription already? Set up your unlimited website access now

Equine vets at the Animal Health Trust (AHT) – who usually deal with large competition horses – have turned their attentions to a rather smaller patient; a 29″ high pony suffering from a painful eye condition.

Prince, a four-year-old miniature pony, who works as a therapy horse, was referred to the AHT’s eye specialists in Newmarket suffering from entropion. The condition causes the eyelids to fold in, making the eyelashes grow inwards and irritate the eye. If untreated, animals with entropion can lose their sight.

Claudia Hartley, who is head of ophthalmology at the AHT, was able to operate and save Prince’s sight.

“He is an absolute darling!” she said. “It’s great for all of the team here when we can help such deserving cases. Enabling Prince to carry on with his therapy work, free of pain and discomfort, is really rewarding for all of us.”

Prince was able to return home to his owner, Amanda Poulton, shortly after his surgery and was expected to be back ‘on duty’, providing therapy at an event the same week.

Mrs Poulton explained: “My husband and I take him and our other pony, Applause, into hospices and local schools to aid the recovery of patients, or learning of students with special needs.”

Stay in touch with all the news in the run-up to and throughout the major shows and events during 2026 and beyond with a Horse & Hound subscription. Subscribe today for all you need to know ahead of these major events, plus online reports on the action as it happens from our expert team of reporters and in-depth analysis in our special commemorative magazines. Have a subscription already? Set up your unlimited website access now

Learn more about eye problems in horses

Conjunctivitis occurs when the pink lining of the eyelids — the conjunctiva — becomes inflamed.

It is the most common disease affecting the equine eye and it always causes it to weep.

Conjunctivitis can be a disease in its own right, or as a follow-on from another eye disease such as uveitis.

Some common causes of conjunctivitis:

• Bacterial infections
• Irritants, such as wind, dust, flies and chemical irritants
• Allergens, such as pollen
• Trauma
• Foreign bodies
• Eyelid deformities, for example when a wound leaves a gap in the eyelid
• Parasites, such as habronema, which cause sores and are common in sunny summers
• Tumours

Treatment of conjunctivitis will depend on the cause.

With the common bacterial conjunctivitis, antibiotics are frequently prescribed as an ointment, gel or drop to be placed in the eye.

To apply rest your hand on the horse’s cheek and gently turn out the lower eyelid so you can squeeze the medicine into the exposed conjunctival sac.

Medication is often easiest to apply at the inner (medial) corner of the eye.

Find out more about eye problems in horses

Vets at the Animal Health Trust (AHT) have restored the sight of an abandoned Welsh pony.

Morris, a Welsh Section C, was rescued in 2008 by Suffolk charity the Horse Rescue Fund after his owner stopped looking after him.

He had cataracts in both eyes and fundraising by the charity enabled him to have his first eye operated on in November 2008.

And a year later the AHS agreed to chip in from its deserving cases fund to pay for the second operation.

David Donaldson, head of equine ophthalmology, at the AHT, said: “Being able to offer our skills and experience to other animal charities is very rewarding because often the animals they’re looking after are the ones who have been treated badly and so desperately need our help. We’re pleased we’re able to improve their lives.”

Morris came back to the AHT over Christmas and now has sight in both eyes.

Sue Albone, of the Horse Rescue Fund said: “We’re very grateful to the AHT for their help. Morris hasn’t had a great time over the last few years but now he has his sight back he’s reforming into a very cheeky chappy!

“Without the AHT, he’d still be blind and his future would look very bleak.”

Stay in touch with all the news in the run-up to and throughout the major shows and events during 2026 and beyond with a Horse & Hound subscription. Subscribe today for all you need to know ahead of these major events, plus online reports on the action as it happens from our expert team of reporters and in-depth analysis in our special commemorative magazines. Have a subscription already? Set up your unlimited website access now

Iris scanning is being developed as a new way of identifying horses.

The first portable equine iris capture and identification system to help track and identify horses is being developed by US research company Sarnoff Corporation, on behalf of Global Animal Management (GAM).

GAM hopes the system could make brands and microchips a thing of the past.

The company claims there is a “worldwide interest in and need for non-invasive, accurate, low-cost alternatives to those currently used”.

“Animal identification is not nearly as efficient or simple as it needs to be,” said Mark Clifton, from Sarnoff, adding that markings can fade over time and can be faked.

But each horse has a unique iris pattern — even identical twins differ.

The system is based on the same James Bond-style technology that is used at UK borders and high security installations to identify people.

It captures the image of the iris with a low-visibility infrared light source. It is effective at a distance and can be used while the horse is moving.

President of the British Equine Veterinary Association (BEVA) Chris House agreed the idea could work, but said it sounded “impractical”.

“Scanning a microchip takes seconds and gives the horse’s information immediately. I can’t see how iris scanning could be more effective than that,” he said.

“You could identify a horse using DNA, but you have to use a method of identification that is practical and simple.”

This news story was first published in Horse & Hound (29 October, ’09)

Stay in touch with all the news in the run-up to and throughout the major shows and events during 2026 and beyond with a Horse & Hound subscription. Subscribe today for all you need to know ahead of these major events, plus online reports on the action as it happens from our expert team of reporters and in-depth analysis in our special commemorative magazines. Have a subscription already? Set up your unlimited website access now

More advice on exercising your horse

Q: I saw Izzy Taylor eventing her horse Briarlands Blackberry whom I understand only has one eye.

The horse has competed at four-star level — what is it like to care for and ride a horse that is blind in one eye?

RP, Worcestershire

According to vet Deborah Pett MRCVS of Cinder Hill Equine Veterinary Clinic in Sussex, if the horse has its head pointing forward, its visual field extends approximately 350°, with small blind spots immediately behind the animal and in front of the nose.

“Each eye is believed to have a visual field of up to 215° (against 150° for humans), which is why horses blind in one eye cope incredibly well, following a period of adaptation,” Deborah explained.

“This will be obvious if the sight is lost suddenly, for example following ocular trauma, although blindness may go unnoticed if the sight is gradually lost over a prolonged period.

“In situations where a horse has to have an eye surgically removed but some sight is remaining, a fly mask with a patch over the affected eye can be worn to encourage adaptation.

“In the early stages of visual impairment in one eye, we advise approaching horses from their visual side, so as not to surprise them,” she said.

“They will also be less likely to bump into things if you avoid clipping the whiskers on their muzzle. When riding, allow the horse to turn his head, if necessary, to see where strange sounds are coming from. Remember that a horse blind in his right eye [offside] can’t see traffic approaching from behind when out hacking, which may cause spooking.

“The loss of vision in one eye also gives reduced depth perception, which has implications in the performance horse, particularly for jumping; although jumping horses with impaired vision are not uncommon,” said Deborah.

“A horse does not rely entirely on binocular vision for depth perception, but also uses visual cues from its surroundings.”

Izzy Taylor took over the ride on Briarlands Blackberry two years after he lost his eye and says it makes no difference to the way she competes.

“Sat on top, you wouldn’t know he only had one eye,” she said. “The only time I have suspected it affected him was at Bramham when, unusually for him, he had a run-out at a coffin with a slanting rail on his blind side.”

The Suzy Smith-trained hurdler Material World won five races, despite losing an eye as a result of an accident on the gallops. The horse began hanging right later in her career, but whether this was due to soreness, was psychological, or was a trait she developed as a result of only having one eye, it was never discovered.

Alayne Marker and Steve Smith run the Rolling Dog Ranch Animal Sanctuary in Montana, USA, rescuing disabled animals.

Alayne explained: “How a horse adapts to being one-eyed has everything to do with his personality, not the loss of the eye itself. A naturally highly strung or spooky horse may become more so after losing an eye but generally, the passage of time is what really helps an animal adapt.”

Information

• Cinder Hill Equine Veterinary Clinic www.cinderhillequinevets.co.uk

• Rolling Dog Ranch Animal Sanctuary www.rollingdogranch.org

• www.blindhorses.org

This Q&A was first published in Horse & Hound (26 March, ’09)

Looking for advice on exercising your horse?

1. Never use random eye medication that you have in stock

Ensure the nozzle of the tube is not contaminated with dirt or discharge. Use a separate tube for each horse to avoid cross-infection. Throw away any partly used tubes when the condition has resolved. All eye medication must be used within a month of the tube being opened.

2. Look for a foggy area

If the eye is weeping and you can see the surface, look for a foggy or cloudy area. This could indicate an ulcer. Also look for foreign bodies or blood in or around the eye. If you see any of these, call your vet.

3. Never try to force the eyelids open

This can damage the eye further. It is far better to allow your vet to do this by using appropriate painkillers.

4. Never pull anything out of the eye

If there is something sticking out of the eyeball, never pull it out, as it may be a part of the inside of the eye, plugging a wound. Also pulling out a foreign body such as a long hair or piece of straw could slice through the surface of the eye.

5. Check with your vet before flushing the eye

If an irritant chemical is splashed into the eye, flushing the eye with clean water may help or use a proper eye wash, but check with your vet first.

6. Prevent rubbing

A horse will often rub an irritated eye, making things worse. One way of preventing a sore eye from being rubbed is to use blinkers. In an emergency, you should stay with a horse to prevent it rubbing while professional help is sought. An ice pack (frozen peas would do) in between layers of soft clean cloth held against the eye for five minutes may help to soothe it and there are purpose-made protective eye masks available. Visit www.horsemask.com or www.guardianmask.com.

7. Use a dark stable

Many horses with eye problems are sensitive to light. They may feel better if placed in a quiet, dust-free, fly-free dark stable.

8. Feed on the floor

Feeding on the floor will help reduce dust irritating an already sore eye.

9. Have eyelid wounds repaired

Any eyelid wound involving the eyelid margin should be repaired by your vet to avoid later complications. They will usually heal very well. If left to heal on their own, you can get serious scarring and damage to the eye itself.

10. Wipe away discharge

Wipe away any discharge around the eye and keep flies away. Application of petroleum jelly around the eye may reduce scalding of the skin.

For the full article on common eye problems and the latest treatments, see the current issue of Horse & Hound (18 December, ’08)

There was considerable interest in 1999 when scientists suggested that when a horse is ridden with the front of the face in a vertical position (a fairly normal contact outline), the visual field of the horse becomes very limited.

We were told that in this position, with the poll flexed and the nose pointing straight downwards, a medium-sized horse could not see more than three metres of ground in front of it.

In order to look further ahead, the theory proposed, a horse has to lift its head and look down its nose; this is why horses raise their heads so high to see things far away. This idea has long worried vets and behavioural scientists.

Recently, scientists in the Czech Republic have returned to these questions, reviewed the evidence and recorded the position of the eyes of horses when the head position and posture changes.

Horses have just about the biggest eyes of any mammal, so it is not difficult to photograph them precisely and work out the position of the pupil and the degree of rotation of the eye as the head is lowered and raised.

The new research shows that it would be true that horses became progressively less able to see in front of them as the head was lowered if the eye remained fixed. But the eye does not remain fixed, it rotates within the orbit so that the oval-shaped pupil remains horizontal in any head position.

As a result scientists believe horses can see in front of them even when the head is lowered, a theory that fits much better with what we clearly see when a show jumper clears the rails with such precision.

This article was first published in Horse & Hound (27 November, ’08)

The owners of a pony stabbed in the eye in Carmarthenshire on Tuesday are offering a reward of £1,000 for information.

Police have now linked the two attacks — this one and the stabbing of a prize-winning stallion in the same area three weeks ago — and are advising owners to make regular checks on their animals.

During the early hours of Tuesday morning, 30-year-old pony Phoenix was attacked in his stable at a yard between Kidwelly and Trimsaran. He was stabbed in the same corner of the same eye as an 11.2hh Welsh Section A stallion was last month.

A spokesman for Kidwelly police confirmed Phoenix could not have injured himself in his stable, and told H&H: “We don’t want to scaremonger, but people should remain vigilant and make regular checks and alter their routines where possible.”

Phoenix’s owners David and Rose Morgan have put up posters locally offering a £1,000 reward for information leading the arrest of those responsible for the stabbing.

“I doubt it will lead to anything but we have to try,” said Mrs Morgan. “It’s heart breaking that anyone can do something like that — it’s absolutely sickening.”

She said that despite the attack, Phoenix has remained calm and trusting with his owners.

On 8 June an 11-year-old champion M&M stallion called Caemoss Aubrey, was stabbed in the eye with a pair of scissors, also in Kidwelly. Owners Stan and Heather Strelley are also offering a £1,000 reward for information.

If you have any information about either attack, contact Kidwelly police on 0845 3302000.

Stay in touch with all the news in the run-up to and throughout the major shows and events during 2026 and beyond with a Horse & Hound subscription. Subscribe today for all you need to know ahead of these major events, plus online reports on the action as it happens from our expert team of reporters and in-depth analysis in our special commemorative magazines. Have a subscription already? Set up your unlimited website access now

Another pony has been stabbed in the eye in Camarthenshire, three weeks after a prize-winning stallion was stabbed in the same area.

The 30-year-old pony — called Phoenix — was attacked in his stable last night at a yard between Kidwelly and Trimsaran. The latest stabbing is just three-quarters of a mile away from where an 11.2hh palomino Welsh Section A stallion was attacked last month. And the owners are linking the two.

Phoenix’s owner David Morgan told H&H: “We heard a noise at 2.30am this morning, there was quite a clutter. We looked out of the bedroom window and saw the pony in the yard — he has COPD so he has a restrainer across his doorway, not a door.”

Mr Morgan said he and his wife, Rose, immediately called both their vet and the local police, after discovering the pony had been stabbed.

Phoenix is a rescue pony and has been with the Morgans for three years. He is a companion for their two show hunters.

“The show hunters were both in at the time, but they’re fairly big so whoever it was picked on the pony, instead,” said Mr Morgan.

Their vet has confirmed the pony was stabbed with a sharp instrument in the corner of his eye. While Phoenix has lost his sight, the vet is assessing whether or not he can save the eye over the next few days.

Rose Morgan told H&H that horse owners in the area are all very aware of the second stabbing.

“We’ve had people ringing us up today that we don’t even know,” she said. “It’s heart breaking that anyone can do something like that — it’s absolutely sickening.”

She said that despite the attack, Phoenix has remained calm and trusting with his owners.

A spokesman for Dyfed Powys police confirmed they attended the incident at 2.56am today, at the same time as the vet.

“The vet confirmed the pony had been injured in the eye,” said a spokesman, who added that it was unknown at present whether the two incidents are linked.

On 8 June an 11-year-old champion M&M stallion called Caemoss Aubrey, was stabbed in the eye with a pair of scissors, also in Kidwelly. Owners Stan and Heather Strelley are offering a £1,000 reward for information.

If you have any information about either attack, contact Kidwelly police on 0845 3302000

Stay in touch with all the news in the run-up to and throughout the major shows and events during 2026 and beyond with a Horse & Hound subscription. Subscribe today for all you need to know ahead of these major events, plus online reports on the action as it happens from our expert team of reporters and in-depth analysis in our special commemorative magazines. Have a subscription already? Set up your unlimited website access now

If the corneal surface of the eye is damaged, the most likely result is an ulcer, which can be very painful. Such corneal injuries are prone to secondary infection by bacteria and fungi, which can, in some unlucky horses, result in the development of deep, non-healing ulcers or abscesses.

Corneal ulcers are so common that they will be the first thing a vet will suspect when presented with a horse with suddenly red, sore, half-closed and weeping eye.

Diagnosis is made following a thorough examination of the eye. Some corneal injuries are readily observed, but very tiny ulcers or abrasions show up more clearly following the application of various coloured dyes that stain them green or pink. The appearance of the lesion can be suggestive of the cause.

Swabs, scrapings or biopsies are sometimes necessary to confirm diagnosis with deep or non-healing ulcers. The material can be examined under the microscope to detect the presence and type of bacteria or fungi. Antibiotic sensitivity testing may also be performed.

Thankfully, treatment of most corneal ulcers is straightforward. Providing the equine patient is amenable to having medication administered to the eye, a short course of antibiotic drops or ointment will rapidly return the eye to normal.

Difficulties arise when the horse objects to anything being put into the sore eye, and if bribes, sedation or a twitch will not improve matters, the vet may insert an indwelling catheter. This allows remote administration of the treatment via soft rubber tubing implanted under the eyelid and then plaited into the mane enabling treatment at a safe distance. There are even sophisticated tiny battery-driven pumps available that permit — at a price — a constant drip of treatment to be pumped into the eye.

Typically, not everything with horses goes according to plan, so although the majority of ulcers will resolve within a few days, a small percentage do not heal within the expected time frame. It can be a really frustrating condition for all concerned, when despite all efforts the eye does not seem to improve. There can be a variety of reasons for this:

• Something continually rubbing on the eye, such as a tiny bit of dirt embedded under the eyelid or, more rarely, an eyelash growing the wrong way or in the wrong place, so it constantly irritates.
• A persistent infection may prevent healing. Bacteria are usually to blame, but in hot, humid areas, especially America, fungal eye infections can be catastrophic. Recently, such cases have been reported in the UK, which could be considered a nasty side effect of global warming.

The most difficult to deal with is the so-called indolent ulcer, where the damaged eye surface becomes unhealthy and unable to heal. These cases may need surgical intervention as well as medical treatment.

Surgery

If eye drops or ointments do not produce a cure, the vet may treat the non-healing ulcer by gently scraping away the area of unhealthy tissue. Sometimes this is achievable with the horse standing, but other cases will require general anaesthesia.

A variety of different procedures can be performed, from a simple scrape to a more elaborate removal of diseased tissue known as a keratotomy. A study of 23 cases suggested that a single debridement, or surgical scrape, early on was beneficial in reducing healing time.

Some cases also benefit from cautery with chemicals, and others are treated by application of a soft contact bandage lens, which helps to protect the eye as it heals.

Some cases end up having more radical surgery under general anaesthesia, where a graft of tissue from the conjunctiva (membranes around the eye) is carefully sutured on to the eye as a natural bandage to encourage healing.

In small animals, such eye problems are sometimes treated by either sewing the third eyelid over the eye or by sewing the eyelids together. However, it is not ideal for the majority of horses, as it conceals what is going on underneath and makes treatment difficult to apply to the eye.

In recent years, treatment techniques have improved and the correct medical therapy and prompt surgical intervention have improved the chance of a successful outcome in many horses who previously would have gone blind.

• This article formed part of a veterinary feature first published in Horse & Hound

Almost all horses have big, beautiful eyes. Unlike their riders, they never wink nor scowl, so if your horse has one eye partially or completely closed, it means something is wrong.

This is known as blepharospasm — it is obvious when the eye is totally shut, but can be harder to appreciate when it is more subtle, unless careful comparison is made between the eyes.

Another clue is photophobia, which is when a horse avoids bright light and is more comfortable in a darkened environment. Such a horse will squint in sunlight or screw the eyelid shut when a light is shone into the eye.

Another sign that something is wrong is profuse tear production or lacrimation. At first, the eye may just water more than normal, but if secondary bacterial infection develops, there will be pus in the discharge. It is all too easy to become accustomed to seeing a slight discharge, particularly associated with flies in summer and dusty stables in winter. As a result, a more significant discharge is sometimes ignored.

Beware of using whatever eye ointment is still sitting at the back of the tackroom cupboard. Eye treatments go off and should never be kept just in case they might be useful: what might be ideal for treating one condition could make another worse, so be cautious and check with your vet first.

What can be done?

If a horse is in obvious discomfort, with its eyelid tightly closed, do not force the eye open. By trying to do so, you could inadvertently apply sufficient pressure to rupture a severely damaged eye. If there is any cause for concern, contact your vet.

Leave the detailed examination to the vet, who can use topical anaesthesia, nerve blocks and sedatives to relax the horse and alleviate the discomfort. Once the pain is removed, the horse may open its eye and be more amenable to examination. The upper eyelid can then be lifted to see the structures underneath.

In addition to looking for external injuries, the vet will also check the internal structures of the eye, usually with a pen torch and an ophthalmoscope, and sometimes more sophisticated kit. This is best carried out in a darkened box. Drops may be put in the eye to dilate the pupil so the inside can be seen in more detail. The vet may carry out a number of other tests, depending on the problem being investigated.

What is most likely to be wrong?

Many common equine eye conditions affect the cornea, which is the clear window at the front of the eye. If this is not healthy, this essential optical barrier goes cloudy and when it is no longer transparent the horse simply cannot see out. The cornea is frighteningly fragile, being only about 1mm thick and prone to injury simply because the equine eye is in such a vulnerable position.

The horse’s ability to move its head rapidly can easily result in trauma. It is impressive that equine eyes ever survive undamaged. This is because the horse has inbuilt protective mechanisms, including a strong blink reflex that closes the eyelid before the eye hits something.

Another hazard for horses is dirt and dust getting into the eye. When you have something in your eye, you can fish it out. It is not so simple if you are a horse with hooves — you have to rely on the natural tear film to wash debris away. This means foreign bodies such as hayseeds and hairs can linger and cause serious damage to the eye surface, which can lead to an ulcer forming.

• This article formed part of a veterinary feature first published in Horse & HoundView more articles about eye problems in the HHO archive >>

There are many causes of lumps developing in and around horses’ eyes, several of them serious and a few of little importance. The difficulty for owners is to know which warrant veterinary attention and which do not. However, for your own peace of mind it has to be worth asking your vet to investigate any lump. It is often helpful if you can tell your vet how quickly the lump has developed. Fast-expanding masses will usually generate more concern.

The majority of lumps will need prompt attention due to their location, even if in themselves they are not important. Anything that affects the movement of the eyelid, or the efficiency with which it wipes the surface of the eye, will have a profound implication for the integrity of the cornea (the clear window of the eye). More than 75% of the blink is done with the upper lid, so deformities and loss of function in it are much more serious than in the lower lid.

Any lump that results in an abnormal rubbing of the cornea is likely to result in an ulcer — this is potentially extremely serious. Some masses are on the eye itself or on the internal membrane of the eye (conjunctiva) and these can vary in their significance.

Lumps in the eyelid

Eyelid lumps are divided into several types based on the cause. First, there are those arising from infection — whether from a wound or other injury or an infection affecting the eyelid glands (so-called “styes”).

Second, there are lumps that arise from some deformity of the skin or its associated glands and hair follicles. These are rare in horses. Quite often, they are spotted incidentally or when the eye starts to produce an abnormal discharge, which may simply be the result of a lack of proper tear drainage from the eye.

Another unusual lump is caused by a prolapse (abnormal positioning) of the fat pad behind and around the eye. This can be alarming but is not always visible. When the horse lowers its head and blinks, the mass may look large and when it is standing and the eye is relaxed, it may disappear altogether. The chief feature of the early stages of this unusual condition is that it causes neither obvious discomfort nor inflammation.

Trauma or bruising of the eyelid can cause serious thickening and obvious bruising of the eyelids (and sometimes of the eye itself). A bruise around the eye associated with swelling should sound a warning bell that there might have been a bout of colic.

Even when a horse is cast, it seldom causes excessive bruising or grazing of the eyelids. With such knocks, the swelling of the eyelid may be relatively trivial, but it should always be checked in case there is deeper damage, for example, on the eye itself.

Virus papilloma (true “warts”) are benign skin tumours that arise from a viral infection. In young horses (usually those under two or three years old) they will invariably resolve without intervention. In older horses there is less tendency to self-cure and some remain for life.

Tumours and tumour-like masses

There are several important tumours that occur in the eyelid regions and these cause some concern. Not all are serious, but almost all will have secondary implications on eyelid function. Some are small but potentially serious, while others are larger and have less long-term, harmful effects. Early recognition is important if treatments are to be effective.

Eyelid melanoma is only common in grey horses. Usually, melanomas remain quite localised and the lower lid is more often involved. This is fortunate because it means treatment involving surgical excision can be carried out relatively easily.

Melanomas can be recognised by their shiny black colour. However, some occur on the inner lining of the eyelid, so, apart from distortion, there may be nothing to see. It may be easy to examine the margin of the lower lid and it is probably worth checking this if a swelling is seen on a grey horse. The inner corner of the eye and the structures inside the eye can also be affected.

We still have no real idea why melanomas develop and even less idea about how to treat them. Apart from surgical removal, which can be difficult, the sole suggested medical approach is the daily administration of a drug called cimetidine. This is used to treat gastric ulcers, but there are reports of it being effective against some melanomas. However, the eyelid is particularly resistant to this approach and very few cases respond to it.

The other option is to leave the mass alone, but this should be reserved for slow-growing localised lesions or those that are clearly impossible to treat. As melanomas are largely the preserve of older grey horses, other masses are common, especially under the tail and around the mouth. A few cases are highly malignant, but these are rare.

Sarcoids and carcinomas

The sarcoid is probably the most common eyelid problem and is potentially serious. Sarcoids appear in many different forms ranging from mild hair loss to large nodules under the skin and fleshy outgrowths. This makes diagnosis difficult, but treatment is easier the earlier it can be applied. By the time the condition is extensive or large, the options for treatment are limited.

The sarcoid doesn’t spread to internal organs, but it is common for a horse to have more than one lesion, so it is always worth checking places such as the groin and girth area. The best form of treatment is radiation — around the eye, this carries a success rate of more than 90%, but it is an expensive and restricted method of treatment. There are other options, but all are less effective. Surgical excision and topical creams are not usually advisable because they will cause tissue destruction and scarring.

One of the most dangerous eyelid tumours is squamous cell carcinoma. This affects the eyelid (or eye) especially in horses with pale eyelid margins or third eyelids. There are two main types of squamous cell carcinoma recognised by vets. The proliferative form appears as larger masses, while the destructive form results in erosion and destruction of the local tissues. The proliferative form is normally followed by the destructive and should be recognised quickly so action can be taken.

This condition also occurs on the surface of the eye, and in all cases there is a risk of malignancy and spread to adjacent structures. In the most advanced cases, the tumour can spread to other internal organs. The options for treatment are again limited by practicality and the need to kill every single tumour cell.

By the time such carcinomas are seen by a vet there is often already extensive destruction of the eyelid margins, so the scope for surgical repair is limited and involves significant reconstructive surgery. Surgical excision of tumours on the cornea and the third eyelid is, however, entirely feasible in most cases, except severely neglected ones.

There are options for medical treatment using anti-cancer eye drops or ointments in early cases, and in some such small tumours it may be possible for freeze the tumour. Inevitably there is risk that either the treatment is applied too late or will not remove the whole lesion. As is typical with cancers of any type, treatment has to kill or remove every single cancer cell — if just one is left behind, there is a strong possibility of recurrence, usually in a more aggressive form.

Although some unusual tumours occur in and around the eye, the most common ones are easily recognised. Confirmation of a diagnosis is usually reliant on biopsy, tissue scrapes or aspirates from the mass. The outlook is often far better than is first appreciated, provided diagnosis is made early.

In very rare types of tumour, it is usually not possible to give an idea of the realistic prognosis, and treatment methods are poorly characterised. Few vets have seen all the options, so in some circumstances the case may be best referred to a specialist centre for diagnosis and treatment.

This veterinary feature was first published in Horse & Hound (2 February ’06)

Cataracts can now be removed from horses’ eyes using techniques previously only used on humans. The pioneering operation has been perfected by vets and ophthalmologists at the University of Liverpool’s Large Animal Hospital at Leahurst, Merseyside, and will save thousands of horses from being put down.

Until now equine cataract operations have rarely been performed in the UK because of the risk of post-operative complications but now the hospital can offer it as routine surgery. Professor Derek Knottenbelt, Liverpool University’s Head of Equine Studies said: “This new surgery shows how effectively the latest human cataract surgical techniques can translate successfully to bear on an equine problem.”

Surgeons at Leahurst have already restored the sight in one eye of a 15-month-old filly who was born blind with cataracts in both eyes. The team is now preparing to operate on the second eye and the horse is expected to make a full recovery.

The veterinary team perfected the operation by adapting a device usually used on humans which breaks up a cataract using an ultrasound probe called a phacoemulsification machine. The surgeons combined that with a technique commonly used in “eye camps” in remote parts of India, to dislodge the cataract using a jet of saline. Finally they found a way to inject horses with steroids to control postoperative inflammation of the eye.

There have already been several success stories at Leahurst. Professor Knottenbelt and Dr. Wong carried out two operations on TC, a nine-year old gelding warmblood with cataracts in both eyes. “I’m absolutely delighted with the outcome of TC’s surgery,” said TC’s owner, Melina. “If I had not agreed to this pioneering operation the only other course of action would have been to have my horse put down. As a showjumping horse, it was vital to have TC’s eyesight restored.”

For further information about equine cataracts and eye surgery, contact the University of Liverpool’s Large Animal Hospital at Leahurst, Wirral, Merseyside (tel: 0151 794 6041).

Stay in touch with all the news in the run-up to and throughout the major shows and events during 2026 and beyond with a Horse & Hound subscription. Subscribe today for all you need to know ahead of these major events, plus online reports on the action as it happens from our expert team of reporters and in-depth analysis in our special commemorative magazines. Have a subscription already? Set up your unlimited website access now

The decision to remove an eye is inevitably based on the need to remove pain and, as such, is rarely a difficult one to make. If a horse loses the sight in one eye but is not in pain, there is no point in removal because it would not be a welfare issue.

Cases that result in eye removal start with injury, uveitis (inflammation frequently associated with moon blindness, which is properly known as equine recurrent uveitis) or both.

Direct trauma is a common starting point; other causes include glaucoma, which causes an increase in pressure within the eye. Cataracts do not necessitate removal and cataract surgery is still relatively unusual in horses compared with people.

Neal Ashton MRCVS, a partner at Oakham Veterinary Hospital, says that eye removal involves “very straightforward” surgery lasting about half an hour under general anaesthetic.

“It’s basically a dissection,” he explains. “There are potential pitfalls, though. For instance, the optic nerve has to be sectioned — cut through — and as it goes from the brain to the eye, there is potential for infection to track back to the brain.

“There are a number of techniques, depending on how many of the structures have to be taken out, such as glands and muscles at the back of the eye. We try to leave as much muscle as possible because it makes the site look more natural and you get some movement and more bulking out.”

Where a prosthesis is recommended on welfare grounds, Neal uses a latex ball to replace the eyeball.

“These are straightforward to use,” he finds. “I’ve only had one case where complications meant it had to be taken out.”

Equine patients stay at the veterinary hospital until five days after the operation and are given antibiotics. They are then box-rested for about two weeks, after which the staples are removed from the site and the horse gradually returns to a normal regime.

Horses who have suddenly lost their sight usually take only a few days to adjust, though careful management and handling is essential and owners have to remember to make the horse aware of their presence before approaching on the blind side.

“A lot of horses are much brighter after surgery because the eye was so painful beforehand,” finds Neal.

Opinions vary about to what extent losing an eye affects a horse’s ability to judge fences.

“It may perhaps have an effect on horses competing at the very highest level, where every centimetre counts,” says Neal Ashton MRCVS, a partner at Oakham Veterinary Hospital. “But most adapt quickly and go back to competition.”

This veterinary feature was first published in Horse & Hound (22 September, ’05)

It is very difficult to assess a horse’s vision. Currently vets can only detect the most major visual impediments in horses, due to the crudeness of the tools we have available.

An ophthalmoscope is the standard instrument used to look inside a horse’s eye. The first thing a vet looks for is any opacity within the lens. This is seen as a dark area that is not transparent to the bright light being shone into the eye. Basically, any such area of the lens that is not “see-through” is a cataract.

It is thought that some form of opacity is present in about 5-7% of horses with otherwise clinically normal eyes. These may be so tiny that they are only picked up with a detailed ophthalmic examination in a darkened stable. The lack of light makes the horse open its pupil wider, so enabling the vet to see more of the inside of the eye.

Cataracts can be a cause for concern when a horse is examined for purchase by a vet, partly because they may have been previously undetected. Most knowledgeable owners have a pretty shrewd idea of their own horses’ defects. Even so, there is often a sigh of relief when the eyes are declared to be clear at a vetting, simply because the inside of the eye can be one area that remains a mystery.

What if a cataract is found?

Horses with small cataracts show no clinical signs. If one is found, it is sensible to have it rechecked six months to a year later to ensure it has not progressed. Many owners do not bother because treatment is not an option, but I recommend having the eye checked to ensure that the horse is still safe to ride.

Where cataracts are causing a progressive loss of sight, the signs can include:

• stumbling
• walking into objects
• an abnormal number of facial injuries
• an alteration in head carriage
• sudden shying
• increased anxiety and jumpiness

The majority do not progress and are unlikely to affect vision, although some cataracts can be assessed only by repeated examination of the eyes on several occasions over a lengthy period of time.

Treatment

Surgery is the only treatment. The decision on whether to operate depends on the severity and cause of any ongoing eye damage. Surgery should be reserved for the eye that has a cataract and nothing else wrong, so a detailed assessment must be carried out to ensure appropriate selection of patients, and that the owners understand all the risks.

Equine cataract surgery is not something to be undertaken lightly and is best avoided if a horse still has one normal eye. Even if the cataract surgery is successful, the treated horse will never have normal vision.

This challenging surgical procedure is performed only by a few highly skilled and intrepid equine ophthalmic surgeons.

Cataract facts

Cataracts may be:

• Congenital (present at birth), possibly due to problems such as infection, poor nutrition or exposure to toxins while the foal was developing in the uterus
• Hereditary — in some breeds these may be present at birth or develop by the age
  of three
• Acquired as a result of injury or disease
• The result of ageing changes and either unilateral (affecting one eye) or bilateral (both eyes).A cataract on its own is not painful, but the eye may be sore if there is other ongoing eye disease, which may have caused the cataract.Unless a cataract is large, the horse’s owner may be unaware of its existence.
  A large cataract may show up as a blue or milky haze within the black pupil. Advanced cataracts may have a yellowish quality, especially if there are other ongoing eye diseases.Although a cataract will not block all the light going into the eye, the affected part of the lens will prevent a meaningful image being produced at that point. Instead, anything in the affected area will look blurred as if seen through dense fog.Cataracts can range from tiny developmental defects with a minimal effect on vision to extensive cataracts that can affect the usefulness or safety of such a horse.Cataracts are part of the normal ageing process and occur in all species of domestic animals as well as man. One survey of 83 horses and ponies over 15 years of age showed that 10 animals had cataracts, yet none was reported to have any visual defect.

This veterinary feature was first published in Horse & Hound (21 July, ’05)

The University of Liverpool has successfully operated on a horse with severe cataracts in a rare surgical procedure, which may ultimately pave the way for other horses with the condition to have their sight restored.

The equine patient, James, was completely blind in his right eye and had only limited vision in his left eye due to cataracts before the operation. His prognosis was poor until Dr Derek Knottenbelt and his team at Liverpool University’s large animal hospital at Leahurst on the Wirral decided to operate.

Dr Knottenbelt explains: “This lovely horse was going to become completely blind unless we operated, but the procedure is a rare and difficult one with major risks. We only went ahead as there was really no other option.

“The procedure took around 40 minutes and involved the removal of the lens in the right eye using ultrasound to disrupt the lens material. James’ cataract was so solid that conventional methods for human lens removal were not possible and so the eye itself was opened and the solid portion removed directly.

“We are grateful to Dr David Wong from the University’s Ophthalmology Research Unit for his help with the surgery.”

Although eye surgery is commonly undertaken in humans and small animals, the horse’s eye is particularly difficult to operate on because it is extremely sensitive and can easily collapse when the internal structure is interfered with.

Dr Knottenbelt continues: “Any work on the horse’s eye makes it susceptible to uveitis, or moon blindness as it is also know, which causes the horse a lot of pain, in addition to a lack of sight. At present James is showing no signs of uveitis and is responding to light and dark, which is fantastic news, although his prognosis remains guarded.”

Dr Knottenbelt hopes to operate on James’s left eye once he has fully recovered from the surgery but is keen to emphasise that his team’s success is only a tiny step forwards in understanding and improving equine eye surgery, an area which is fraught with dangers.

“We are trying to develop ways of increasing the chances of a successful outcome and the restoration of sight. We are determined to improve the outlook for horses that would otherwise be condemned,” he says.

The horse’s owner, Tony Sumpton, was pleased with the outcome of the initial operation.

“I am extremely grateful to Dr Knottenbelt,” says Tony. “James is showing good signs of recovery and we hope the operation on his left eye will be an equal success.”

Stay in touch with all the news in the run-up to and throughout the major shows and events during 2026 and beyond with a Horse & Hound subscription. Subscribe today for all you need to know ahead of these major events, plus online reports on the action as it happens from our expert team of reporters and in-depth analysis in our special commemorative magazines. Have a subscription already? Set up your unlimited website access now

Equine eyes are located on the sides of the head, giving horses a much larger field of view than humans. With head held at normal height, they possess an almost complete field of vision around them.

The relatively forward position of the eyes provides a binocular overlap of about 55 to 65 degrees – in humans it is 120 degrees.

Blind areas exist only within a narrow region to the rear and in a small area perpendicular to the forehead and directly below the nose. Even so, a tiny shift of the head is enough to bring these areas into view.

Scientists have disproved the popular ramp retina theory, according to which horses brought objects into focus by raising or lowering their head so that images could fall onto different areas of the retina.

Research shows that the equine retina contains a narrow horizontal streak across the centre of the eye, which is densely packed with receptor cells called cones. This provides a band of acute vision.

Colour vision

Equine colour vision has been debated for years. In reality it seems horses are like humans with colour vision deficiencies.

Equine vision expert Dr Brian Timney, of the University of Western Ontario, explains: “Horses have little difficulty in discriminating red or blue from grey but with green and yellow, the results are mixed.”

Behavioural data, along with physical evidence that horses possess at least two types of cones (a must for some degree of colour vision), indicates that horses do see certain colours.

Research into horses’ night vision remains sparse, but the indications are that they see much better than humans in low light.

The equine retina has nine times as many rod receptors as cones. These receptors are responsible for vision in low light. This suggests good night vision.

So, how well does the horse see at a distance? Put it this way, if you are even moderately short-sighted, the chances are your horse can see better than you. Normal human vision is 20/20 – horses are rated at 20/30.

Research suggests that horses can also perceive depth. “Apparently, horses have many of the same depth-detecting skills that we have,” says Dr Timney. “They have true stereoscopic vision, despite having lateral eyes.”

So the horse’s visual world doesn’t differ much from ours – a little less colourful, a little bit blurry, but much broader and more useful at all times of the day and night.

The horse’s eyes look quite different from ours but essentially function similarly in many ways. As owners, trainers, handlers and caretakers, we must carefully consider this.

Fascinating facts

1. With almost panoramic vision, horses can see objects and movements that you would miss. Next time your horse becomes nervous, take a good look around, use your senses and watch his ears – they will be pointed at the object of his interest.

2. If you want your horse to clearly see where he is going, don’t ride him with his face set vertically. Researcher Alison Harman, from the University of Western Australia, found that, due to the visual streak, the horse’s binocular vision is directed down the nose. This means that if his face is vertical, he is confined to looking down at the ground and must rely on you for direction.

3. Be aware that horses may make colour associations – both positive and negative. If you always wear a blue shirt when involved in an unpleasant activity nearyour horse, he may start avoiding you, or anyone else, dressed in blue. Similarly, if your horse regularly avoids certain jumps, it’s worth considering that it could be because of the colour.

4. Trust your horse if riding after dark. You mightnot be able to see where you’re going, but he probably does. However, when quickly going from bright light to dim light, the equine eye needs time to adapt. Horses sometimes balk at barn or trailer doors simply because they cannot see inside.

5. Allow show jumpers to change the angle of their heads so they can use their depth perception to judge fences upon approach. You should train your horse to be responsible on a loose rein. Restricted riding with short reins limits vision, which often causes anxiety and can be dangerous.

6. Give your horse the chance to look around and investigate his surroundings. Both curious and cautious by nature, horses appreciate a handler or rider who acknowledges the way they think and perceive, so be patient.

If your horse keeps his eye closed, it means it hurts. Infections, inflammation and foreign bodies in the eye can all cause him discomfort and an obvious discharge from the eye itself. Don’t ignore it, contact your vet.

What to do

• Wipe away any discharge you can and keep flies off the eye.You can apply Vaseline around the eye to reduce the skin being scalded by the discharge.Never try to force the eyelids open if they are shut as you could damage the eye further.
• If something is sticking out of the eyeball, don’t pull it out, as it could be a part of the eye itself. If you can, gently bathe around the eye. Boiled then cooled water is best in an emergency.If an irritant chemical has been splashed into the eye, flush it with clean water. If in doubt, consult your vet.
• A horse will often try to rub an injured eye, making it worse. Use a pair of blinkers to protect the eye or stay with your horse to stop him rubbing it while professional help is sought.If possible, an ice pack in between layers of soft cloth may help to soothe it.

REMEMBER

• Many horses with eye problems are sensitive to light. Place them in a quiet, dust-free, dark, fly-free stable. Feed hay on the floor (as opposed to a haynet) to minimise dust getting in their eyes.
• Any eyelid wound involving the eyelid margin should be repaired by your vet to avoid later complications.

Just how much a horse can see with each eye is extremely difficult to assess. Usually, a test is done with an obstacle course made up of boxes, buckets, brooms and bales of hay. It can be performed with one eye blindfolded, both in the semi-dark and in bright light.

Night vision is less effective in horses than in truly nocturnal animals. Colour vision is thought to be poor – yellow is reported to be the “best” colour for horses and red, green and blue less well-appreciated.

Gradual loss of vision in one eye is well tolerated by most horses and many give the impression that they are fullysighted. While this adaptability is good for the horse, it can make it difficult for a vet to diagnose.

Sudden, total loss of vision in both eyes, which can occur with retinal detachment or with brain trauma, is distressing. Affected horses often have a startled look, with wide-open eyes, dilated pupils and sharply pricked ears. They may overreact to sounds or touch and can be dangerous to handle.

How much can he see?

When a horse stands with its head held squarely on its neck it can see all around its body, except for a 1-2ø wedge starting behind the back of the head and a small area of the face, poll and ears – a slight movement of the head to either side is enough to allow the horse to see the missing wedge.

Peripheral vision may sometimes be less efficient and approaching objects can often startle some horses.

The horse has a limited field of stereoscopic or binocular vision in front of it. This is relatively small because the eyes are set in the side of the head and do not face directly forward.

Co-ordinated movement of the eyes is controlled with pinpoint accuracy by muscles attached to the eyeball, which are controlled by voluntary movement and reflex connections to the balance mechanisms in the middle ear.

The horse focuses through lens alterations and changes in the shape of the eyeball itself. Horses seldom miss their step and can often be seen to make tiny adjustments to foot placement in response to the going

Some horses have been shown to be short-sighted, but the full effect on the horse is not known but it may explain why some shy or hesitate in certain conditions.

Adjusting to light

The eye has to adjust to the available light, and the iris opens or closes to compensate for any changes. This is a complicated process involving several different nerve pathways. Response of the iris (pupil) to light does not necessarily mean that the horse can see.

The brain

The optic cortex area of the brain is responsible for vision and trauma to the back of the head can cause blindness, resulting from a failure of this area to recognise the signals coming from the eye.

Although the eyes can appear quite normal, the horse may be totally or partially blind. Signals are also sent from the optic pathways to other parts of the brain that control pupil diameter and balance.

Eye injuries/b>

Despite the eye’s prominence on the head, injuries are unusual, damage is more common on the eyelids because the head does not move as fast as the eyelids do to protect the eye.

A horse, which blinks if an open hand is suddenly shown to the eye, will probably have sight in that eye. If there is no blink, it is possible that the eye is not sighted or that the eyelids cannot respond.

The equine eye is made up of a tough, elastic, slightly oval globe, divided into two compartments, each of which contain fluids. Muscles control the eye’s movement.

Functionally, the eye may be compared with a simple camera &ndash the eyelids protect the eye like a lens-hood, the iris controls the amount of light entering the eye and the lens adjusts the focus of the image on the retina.

Eyelids

The eyelids are susceptible to damage in their role as protection to the eye. A vet is needed to repair any damage as loss of lid shape can lead to problems due to infection. A constant “windscreen wiper” effect of the lids over the cornea is essential to keep it healthy.

Conjunctiva

The protective lining layer surrounding the eye is known as the conjunctiva. Problems in this area cause the majority of veterinary visits involving the equine eye. Conjunctivitis in grazing horses is common, particularly during the summer months. Marked by tears and a thickening of the conjunctiva, most cases respond rapidly to topical antibiotic ointments.

Cornea

The clear surface of the eye – the cornea – is frequently damaged accidentally. The extent of the damage needs to be recognised without delay. As with many eye conditions, the main symptoms are:

• a reluctance to face bright light
• tightly closed eyelids
• excessive tear formation.

Corneal damage is often not visible to the naked eye and is only obvious after applying a fluorescent stain. Untreated damage to the cornea can lead to ulceration of the surface,which may ultimately result in blindness. Cloudiness can be caused by a fungal infection, which should clear up with an appropriate anti-fungal treatment.

Iris

Occasionally, small brown cyst-like growths appear on the iris at the edgeof the pupil. If large enough to cover the whole pupil, the horse’s sight will be affected.

Inflammation of the iris – uveitis – can cause acute discomfort and make the horse reluctant to open his eye, although there may not be any more tears than normal. When you part the lids, you will find the pupil contracted compared with an unaffected eye.

Treatment is atropine, applied locally, to counteract muscular spasm of the iris, and is usually combined with topical steroids. Most cases show a good response in two to three weeks. Reoccurring cases are called periodic ophthalmia or “moon-blindness”.

Lens

Apart from being displaced as a result of severe trauma, the most common lens condition is cataract. This termapplies to any lens opacity and is often only discovered during a routine eye examination, such as at pre-purchase. Although seen in foals (congenital cataract), most are found in mature or ageing horses.

Most cases are thought to originate from a previous case of uveitis, but it may simply be old age. Unless the opacity is severe, there will be little visual impairment and should not affect performance. However, some cataracts are progressive, which will eventually lead to blindness.

Retina

Located at the rear of the eye, the retina is fundamental for vision. The retina can become detached as a result of severe trauma or as a complication from an existing inflammation. However, the horse owner cannot detect this – onlyan ophthalmic examination by the vet can do this.

If your horse has an eye injury, or you suspect a problem with the internal structures of the eye, approach the horse carefully and speak to him as he may be suffering from impaired vision.

If a foreign object is in the eye, try and flush it out with clean water, using a syringe.

If an object, such as a thorn, is penetrating the eye, do not take any action until the vet arrives.

Lacerations or wounds on the eyelid or around the eye should be treated with extreme care.Gently apply pressure with a sterile pad to stop the bleeding and cleanse the wound with water and cotton wool. The wound may need suturing, so contact your vet as soon as you possibly can.

If your horse is showing any of the following symptoms, you will need to contact your vet for further advice or treatment:

• Swelling and discomfort
• Closing of the eye
• Weeping
• Discharge
• Bleeding
• Red ocular membranes