The equine eye is very sensitive, and even the slightest injury can result in blindness. | Photo: Anne M. Eberhardt/The Horse

Editor’s Note: This article was revised by the author to reflect new and updated information in November 2017.

The equine eye is very sensitive, and even the slightest injury can result in blindness. While vision in only one eye does not mean the horse must be euthanized, it does somewhat limit the athletic and working potential of that animal. This article discusses the anatomy and physiology of the eye, complete with drawings and photographs.

Anatomy and Physiology

Orbit—Orbit refers to the bony socket of the skull that contains the eyeball or globe, and the surrounding nerves, blood vessels, fat, connective tissue, and muscle. The equine orbit is a large, conical cavity protected by a complete bony rim. Respiratory sinuses border the horse orbit on the midline (center of the head)