In general, inherited ophthalmic conditions in cats are uncommon. There have been occasional anecdotal reports of a variety of ocular conditions which may be hereditary, but these are mostly unproven (see other sections). Such conditions include eyelid agenesis (lack of eyelids), entropion (turned-in eyelids), nictitans gland protrusion (protrusion of the third eyelid), dermoid (piece of skin on the corneal), corneal sequestration (dense brown/black material in the usually clear part of the eye), persistent pupillary membrane remnants (tags of tissue in the eye attached to the lens), glaucoma (increased pressure in the eye), cataract (cloudiness of the lens), lens luxation, retinal dysplasia and retinal degeneration.

Glaze MB (2005). Congenital and hereditary ocular abnormalities in cats. Clinical-Techniques-in-Small-Animal-Practice. 2005; 20(2): 74-82