Corneal dystrophy. Close-up of an eye with corneal dystrophy stained green with fluorescein dye. Corneal dystrophy is impaired nourishment to the cornea, the clear front part of the eye. Here it is recognisable by the fingerprint-like pattern of grooves over the front of the eye. This patient had a history of dry eye, a condition of poor eyeball lubrication, and herpes simplex virus infection. Fluorescein is a dye which glows with a brilliant green colour when light shines on it.