Most commony their are bacterial (like staph or strep) but can also be caused by a virus, fungus, or other organisms. They can sometimes be extremely serious and proper diagnosis and treatment is essential.
MJK MD
Dear megert,
Corneal ulcers may be associated with sinus infections, contact lens wear, infections of the eyelid margin as an example.
Dr. Feldman
Sandy T. Feldman, M.D., M.S.
ClearView Eye and Laser Medical Center
San Diego, California