A corneal ulcer is an open sore in the cornea. It is usually produced by an infection, commonly bacterial, fungal or viral. The ulcer can either be located in the center of the cornea and greatly affect the vision or be placed in the periphery and not affect it so much. There are at least 25,000 cases of bacterial and fungal corneal ulcers each in India every year. Infections that develop in the cornea are frequently associated with trauma, contact lens overuse and dry eyes.