How horses see: field of view, blind spots and acuity

What does a horse see is a question clients may ask about equine vision. [1] The lecture describes a nearly 360-degree visual field in horses. [1] However, their binocular visual field is very narrow. [1] Their visual acuity is pretty good from a companion-animal standpoint. [1]

Where the visual field ends

Horses have eyes placed laterally, giving them a visual field that extends nearly all the way around them. [1] Their blind spots are directly behind the tail and directly beneath the nose. [1] The presenter relates this broad field to horses being a prey species that needs to know when something is trying to sneak up on them. [1]

Why a horse turns to look

A horse's binocular visual field is very narrow. [1] When something catches its attention, the horse turns to bring that object into the binocular field so it can study it. [1] The lecture connects that behaviour with a prey species needing to know what is happening around it and being able to run from a predator. [1]

How clearly horses see

The lecture describes equine visual acuity as better than that of dogs and cats, and not much worse than human visual acuity. [1] It also describes horses as having little accommodation ability, a feature that is not unique in the animal world. [1]

The horse's iris has a horizontal ellipse pupil. [1] When horses are out on the open plains, the pupil can constrict down to a narrow horizontal slit. [1] Structures at the top of the pupil function like a sun visor. [1] They further regulate the amount of light coming in, so that horses don't have degraded vision and too much glare. [1]

Horses commonly have brown irises, but blue irises and combinations of blue and brown also occur, either within one eye or between eyes. [1] The lecture describes that colour variation as a variation of normal and says it is not a concern. [1]

What colours horses appreciate

Horses have two types of colour cones, whereas humans have trichromatic vision. [1] The lecture describes their more limited spectrum of colour appreciation in terms of yellows, greys and blues. [1] Horses can see something that is red, but they see it as a different tone rather than as red. [1]

Three points to take away

The horse's visual field is nearly 360 degrees, with blind spots behind the tail and beneath the nose. [1] Its binocular field, however, is very narrow. [1]

• Horses turn to study something that catches their attention. [1]
• Horses' visual acuity ranges from about 20/30 to 20/60, which is not that much worse than ours. [1]
• They have colour vision and can see something that is red but their colour vision covers a more limited spectrum of colour appreciation. [1]

The lecture describes horses as able to discern and examine some of the things humans notice. [1] Their appreciation of colour includes differences in colour, but not the richness humans are used to. [1]

Related lectures

On-demand lecture

Introduction To Equine Ophthalmology

References

• Introduction to Equine Ophthalmology (lecture recording, May 8 2026) Vet On It lecture transcriptLecture source retained by Vet On It.