Vision loss affects each horse's welfare differently, so, your veterinarian's recommended treatment will vary with it. | Photo: iStock

Would you know if your horse was losing his eyesight? Moreover, what could you do? 

It might appear that your horses are grazing in the field without a care in the world when, in reality, all of their senses, particularly their vision, are in “red alert” mode, actively monitoring the environment for potential danger. Their large eyes with horizontally fashioned, elliptically shaped pupils help maximize their ability to scan the horizon.

“Not only are horses reliant on their vision for safety as a prey species, they also require excellent vision as athletes,” says Ann E. Dwyer, DVM, a private practitioner at Genesee Valley Equine Clinic, in Scottsville, New York, and past president of the American Association of Equine Practitioners (AAEP). “Thus, declining eyesight in these animals can have devastating consequences for their handler or rider, other horses in the herd, and themselves.”

As many owners know from personal experience, ocular tissues are extremely sensitive. Infection, trauma, dry eye, and increased intraocular pressure (glaucoma) can range from extremely irritating to downright agonizing for people. An acutely red, painful, and irritated eye in your horse that he continues to rub clearly indicates a problem mandating a veterinary visit