Conjunctivitis due to allergies is rare in cats. Corneal ulcers. Ulcers are when the outermost layer of the eye, the clear cornea, is damaged. If left untreated, ulcers can become deeper and ...

Most corneal ulcers are the result of some kind of trauma, usually a scratch from a cat fight or the result of a cat rubbing its eye against a sharp object, like a thorn on a rose bush.