Tear‐deficient dry eye (keratoconjunctivities sicca), and evaporative dry eye, with some overlap between these two categories, are two major categories of dry eye recognized in the horse. Careful examination of the eyelid margins, the inner and outer surfaces of the upper and lower eyelids, assessment of blink and third eyelid movement, specific testing of tear production, assessment of corneal sensitivity, and slit‐lamp examination of the ocular surface before and after fluorescein dye application is recommended to detect dry eye problems. Rose Bengal dye application is also recommended in many cases. Facial nerve paresis is a possible complicating factor in some instances. Evaporative dry eye deserves closer scrutiny for it may be a contributory factor when ocular surface disease such as keratomycosis is present. Factors which influence ocular surface health need more close examination in horses.

From: Tear‐deficient and evaporative dry eye syndromes of the horse by Sheila M. Crispin


What are the 3 areas Ophthalmologists always talk about when treating KCS? Vizoovet has been proven effective in all 3. 1 Increase tear flow. 2. normalize the osmolarity which takes the pain away and the most common comment from clients is how it made their horse much more comfortable. 3 Increases tear film breakup time. This is extremely important because the anterior segment has no blood supply and all the oxygen, exchange of gasses and removal of waste comes from tears. The longer the tear film stays on the eye the more these exchanges and absorptions occur.