Horse Vision - an Overview
- 3 days ago
- 6 min read
Have you ever wondered how horses see the world around them? Understanding the intricacies of horse vision can provide valuable insights into their behavior and wellbeing.
Did you know that horses have a panoramic field of vision of approximately 350 degrees? This ability allows them to detect predators and danger from a distance.
Wide Field of Vision: The lateral positioning of their eyes means horses have a nearly 340-degree field of vision, allowing them to detect movement from almost all directions. This enables them to constantly monitor their environment while grazing.
Blind spots: horses can’t see directly in front of them and directly behind them. Be aware when you are in those spaces, they can't see you.
Monocular & Binocular Vision: They can use one eye at a time (monocular vision) or both eyes together (binocular vision) to focus on objects.
Night Vision: Horses have a 'tapetum lucidum', a reflective layer in their eyes that enhances their ability to see in low light.
Horizontal Pupils: Their oval-shaped pupils help them scan the horizon for potential threats, and allow for maximum light capture.
Colour Perception: Horses see fewer colours than humans, primarily shades of blue and yellow, but their vision is well-suited for detecting movement.
A horse's eyes are safeguarded by not only the same eyelids seen in humans but also a nictitating membrane, or third eyelid. This extra layer is whitish pink in color and is located beneath the other eyelids at the inner corner of the eye, near the nose. When necessary, the third eyelid extends upward to shield the eye from potential scratches or to respond to inflammation, providing an added level of protection.
This article talks more about how horses see. One of the things I took away from this article was giving them a lot of rein around obstacles - both in-hand and under saddle - because they need to raise and lower their head to assess depth, and navigate terrain.
There was a recent article from Warwick Schiller about touching a horse between the eyes.
While I greatly respect his training ideas, I really do wish Schiller would point out that a huge proportion of the horses that he works with are clearly magnesium deficient, which contributes to spookiness and anxiousness. If owners of highly reactive horses would try a magnesium supplement like Calm Mix then they could sift out which elements of their 'worry cup' arise from mineral deficiencies and which are behavioural, but anyway - that's an aside.
He was pointing out that horses don't actually like you touching them between the eyes because that's their blind spot. You need to have an established relationship with a horse before you touch them between the eyes.
For those of you who have been following our journey with little Martha on social media, since reading that I have stopped attempting to touch her between the eyes, and I have had a positive response from her. I have also been way more patient with her in the paddock, waiting for her to offer her muzzle and her feet, and generally waiting for her to approach me - which she does. I'm adopting a no touching until I'm invited strategy which seems to be building trust with her.
This is link to that article on Facebook.
Before we get into problems with eyes - some horse breeds are more prone to blindness. Appaloosas are at the top of that list. We have a blind appaloosa here at Sound Advice. Euthanasia is not inevitable. It is totally possible to have a blind horse who is happy and safe and can have a long life. Our appaloosa blind mare, Rose, is in her mid 30s. Her vision has been poor for around 10 years, and she has been blind for about 6 years. She has always been photosensitive, so she wears a fly mask.
She was a very safe and happy mount for our children even as her vision diminished. She lives in the same familiar paddock that she was in when she could see.
We keep to a very structured routine, so she knows where to go at meal times, and when to head out and graze. We always have our phones playing music or a podcast so that she can assess where we are in her environment. We talk the whole time we’re handling her, so that she knows which human we are. We also have verbal cues to announce what we’re about to do (like rugging or negotiating a gate).
She has a “seeing eye” companion horse that she relies on to shepherd her. Rose will call out for her companion if she can’t hear her, and Kazrah will circle back around and pick her up.
Here is my daughter back in 2018 (mid-drought) negotiating objects with our partially-blind horse.
Here is the same horse today with her seeing-eye horse.
Common Eye Problems in Horses
Horses can experience a variety of eye problems, some of which require urgent attention.
Signs of an eye condition affecting a horse’s sight may include:
Clumsy behavior
Higher incidence of self-trauma (injuries)
Reluctance to move (especially from a lighted area to a dark one)
Spooky behavior
Head shaking
Here are some common issues:
Eye Ulcers: Scratches or injuries to the eye surface can lead to ulcers, which may become serious if left untreated. They can be treated with a topical antibiotic.
Equine Recurrent Uveitis (ERU): Also known as "moon blindness," this autoimmune condition causes repeated inflammation and can lead to vision loss. Complications related to uveitis are the leading cause of blindness in horses worldwide. Uveitis is 8 times more likely in appaloosas, and they are 4 times more likely to go blind in one or both eyes as a result of uveitis.
Conjunctivitis: Inflammation of the conjunctiva, often caused by dust, allergens, or infections. It can be treated with antihistamines.
Cataracts: Clouding of the lens, which can impair vision and may require surgery.
Eyelid lacerations (rips or tears in the eyelid) are common in horses. They must be repaired quickly to avoid infection, reduce swelling, and prevent further damage to the eye. In many cases, your veterinarian will clean the wound and use stitches to repair it so that minimal scarring occurs.
Corneal Injuries: Trauma from debris, branches, or other objects can cause scratches or deeper wounds.
Sensitivity to Light: Some horses develop photophobia, making them uncomfortable in bright conditions. You can improve their comfort with fly veils.
Entropion is a condition where the edges of the eyelid turn inward, causing the eyelashes to rub against the surface of the eye. In foals, it appears as a congenital defect, while in older horses, it can develop due to chronic eye irritation, eyelid scarring, or muscle spasms. This inward rolling of the eyelid leads to discomfort and inflammation of the conjunctiva and cornea. If left untreated, entropion can result in scarring, changes in eye pigmentation, and potentially the formation of slow-healing ulcers on the cornea.
Inflammation of the eyelids (blepharitis) can result from the spreading of a generalized inflammation of the skin (dermatitis), conjunctivitis (inflammation of the conjunctiva), local glandular infections, or irritants such as plant oils or sunlight. Infection with certain fungi or bacteria can also lead to inflammation of the eyelids; however, this is uncommon in horses. To treat blepharitis, your veterinarian may recommend both oral and eye medications. Frequently cleansing the eyes with a warm washcloth may also be necessary.
Blepharitis can also be caused by parasites. Eye parasites in horses, particularly eyeworm disease (Thelaziasis), occur in many regions worldwide, including North America, Europe, Asia, and South America. There have been cases in Australia but it’s not as common. The condition is caused by Thelazia spp., a parasite transmitted by face flies, which deposit infective larvae into the horse’s eye during feeding.
Infections tend to be more common in warmer seasons, when fly activity increases. Horses in areas with high fly populations are at greater risk, making fly control measures essential for prevention.
You can find a good overview here:
Other resources:
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