Most corneal diseases are either infections, degenerations or dystrophies.

Infectious may be bacterial, fungal, viral or protozoan.The most common infections are  bacterial (staph or strep) or viral (herpes).

Corneal dystrophies are bilateral, inherited progressive corneal disorders. There are several different types.

Corneal degenerations are often bilateral. The most commonly seen  are keratoconus and Fuchs dystrophy.