Equine eyes are fascinating sensory organs that serve the practical purpose of sight through a series of complex functions, which dazzle the minds of scientists and horse lovers alike. The eye functions similarly to that of other mammals, but a horse owner does not see or perceive the world in the same manner. This is a look into the complexities of equine vision perceptions, anatomy, and potential problems for the curious horse owner or fellow enthusiast.

The World Through a Horse’s Eyes

Horses possess the ability to see almost 360 degrees because they possess monocular vision, or the capability to use the eyes independent of one another. Two blind spots found directly in front and behind the horse, hinder the range of vision for the horse. Monocular vision causes weak depth perception and limitations in binocular vision or use of the eyes at the same time unlike the vision of people. Horse vision is very sensitive to light and motion which aid in survival from predators.

The Equine Eye Anatomy

Horse eyes possess a similar structure to that of people and most other mammals. The light-sensitive retina is a piece of brain tissue that is enclosed by the eyeball or globe, which provides a pathway for light to reach the retina. The retina transforms the light information into a neural message to the optic nerve, which then sends the message to the brain for visual processing and image conversion. Three eyelids protect the eye from the external environment. The cornea, found on the outside of the globe, is responsible for transmitting and bending light into the eye as well as internal protection. The sclera also functions as protection from external environment. The iris and ciliary body, found in the middle of the eye, work to control light entrance and focusing. The lens is found behind the iris and it serves to provide a focused image for the retina by bending light. The eye components, aqueous humor and choroid serve to nourish other elements of the eye like the retina and cornea.

Identifying Equine Eye Problems

Eyes are very sensitive organs that are susceptible to many problems. Just like humans, horses experience the same discomfort and irritation that people feel with eye problems. The most common eye complications observed in horse eyes include traumatic injuries, corneal disorders, uveitis or internal eye inflammation, cancer on or around eye, and cataracts. Many of these issues and other less serious conditions create similar symptoms, but any irregularity should be taken seriously. When examining the eye, horse owners should look for abnormalities including swollen eyelids, reddened eyes, excessive tearing, excessive squinting and blinking, cloudiness, excessive eye rubbing, foreign objects in eye, growth on eyeball, a creamy color eye, and melting appearances. Veterinary assistance should be sought immediately if these behaviors are observed.

The equine eye is capable of serving many amazing functions, but with complexity comes the potential for a number of problems that horse owners should actively watch for in their pets.

Sources: Vetmed.ucdavis.edu - http://www.vetmed.ucdavis.edu/ceh/docs/horsereport/pubs-HR27-1-bkm-sec.pdf