What you see. The starting point for addressing any equine health related issue is your observation.


Eye looks Cloudy or Gray, All or Part


There are several structures that can impart a gray or cloudy appearance to the eye.

The outer, clear layer of the eye is the cornea. Gray or cloudiness in the cornea is an indication of either fluid (edema) or scarring within the tissue of the cornea. Edema results from injury or inflammation and is commonly associated with corneal ulcers, wounds, and Equine Recurrent Uveitis (ERU or Moon Blindness).

Rarely, graying of the cornea of both eyes might be associated with body-wide (systemic) illness like certain viral diseases. Horses with old corneal scarring from prior injury may have a clearly demarcated white or gray spot on the cornea.

Another structure that can cause an eye to look cloudy is the front chamber of the eye, known as the anterior chamber. If the fluid in this chamber becomes inflamed, it can make the whole eye appear gray. This is classically seen in Equine Recurrent Uveitis (ERU).

Inside the pupil and toward the back of the eye, a normal lens is also clear. Horses with cataracts have graying of the lens, which appears as a white or gray spot which is obviously inside the eyeball and more specifically within the pupil. This is usually a slowly developing problem.

  • Code Red

    Call Your Vet Immediately, Even Outside Business Hours
    • If you notice other problems with the eye or the eye seems inflamed and painful.
    • Most eye problems are considered veterinary emergencies.
  • Code Orange

    Call Your Vet at Their First Available Office Hours
    • If the signs are very mild and the eye appears normal otherwise.
    • The eye does not seem painful and the horse does not seem distressed.

your role


What To Do

When in doubt about the appearance of your horse's eyes, compare left to right, and assess your horse's general health using the Whole Horse Exam (WHE). Look for other eye signs, like watering or discharge, squinting, or reddening. Consider whether the horse seems in pain and whether the condition is changing or static. Given the importance of your horse's sight, do not allow this condition to continue or worsen over time. Contact your vet with your findings and concerns.

your vet's role

Your vet assesses general health and the eye itself. In many cases, they will stain the eye with a green dye- fluorescein, which helps to rule out corneal abrasion or ulcer. In some cases, they will sedate or use regional nerve blocks to better examine the eye and the nearby structures.
Questions Your Vet Might Ask:
  • Does the eye seem irritated too?
  • Is the horse showing signs of eye discomfort like squinting or blinking or holding the eye closed?
  • Is the horse's eye tearing or watering?
  • When did you first notice this change?
  • Does the eye seem inflamed or abnormal in any other way?
  • Is there swelling of the area around your horse's eye?
  • Is the problem affecting one or both eyes?
  • How does it compare to the other eye?
  • Do you see any foreign material in the eye?
  • What are the results of the Whole Horse Exam (WHE)?

Diagnoses Your Vet May Consider

The cause of the problem. These are conditions or ailments that are the cause of the observations you make.

Very Common
Less Common
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Treatments Your Vet May Recommend

A way to resolve the condition or diagnosis. Resolving the underlying cause or treating the signs of disease (symptomatic treatment)

Very Common
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further reading & resources

Author: Doug Thal DVM Dipl. ABVP