The cornea is a clear, window-like structure on the surface of the eye. Since the cornea is the outside layer of the eye, it is more susceptible to damage and irritation. Pigmentary keratitis is a build up of dark scar tissue on the cornea. It appears as a brown pigment that may gradually cover the cornea over time. The pigment could affect vision for the pet, as it covers over the pupil. This corneal response to irritation can be caused by numerous things. Most often, this is a symptom of some other underline problem such as; dry eye disease, entropion, ulcers, abrasions, or overexposure to the elements. Another factor that can contribute to corneal irritation is a condition called lagophthalmos- the inability to fully cover and protect the cornea and distribute a tear film effectively. Some breeds are naturally predispose. When pigmentary keratitis is the diagnosis, a variety of treatment plans can be suggested.