A corneal ulcer is an open sore on the cornea. The cornea covers the iris and the round pupil, much like a watch crystal covers the face of a watch. A corneal ulcer usually results from an eye infection, but severe dry eye or other eye disorders can cause it.

Symptoms of corneal ulcers include:

• redness of the eye
• severe pain and soreness of the eye
• the feeling of having something in your eye
• tearing
• pus or other discharge
• blurred vision
• sensitivity to light
• swelling of the eyelids
• a white spot on your cornea that you may or may not be able to see when looking in the mirror

People at risk for corneal ulcers include:

• contact lens wearers
• people who have or have had cold sores, chicken pox or shingles
• people who use steroid eye drops
• people with dry eye
• people with eyelid disorders that prevent proper functioning of the eyelid
• people who injure or burn their cornea

If you wear contact lenses, safe handling, storage and cleaning of your lenses are key steps to reduce your risk of a corneal ulcer. It is important to learn how to take care of your contact lenses.

See your ophthalmologist immediately if you think you have a corneal ulcer or have any eye symptoms that concern you. Corneal ulcers can badly and permanently damage your vision and even cause blindness if they are not treated.