A corneal ulcer is an open lesion on the cornea, the clear, outer layer at the front of your eye that covers your iris and your pupil. A corneal ulcer is also called keratitis.

Causes of corneal ulcer

A corneal ulcer usually happens because of an eye infection. This could be a viral, bacterial or fungal infection.

A corneal ulcer may result from wearing contact lenses. Dry eye syndrome can also lead to a corneal ulcer, as can abrasions or burns to the cornea. Bell’s palsy and other eyelid disorders that prevent the eyelid from functioning properly can dry the cornea and an ulcer can form.

You’re at risk for a corneal ulcer if you wear contact lenses; you’ve had cold sores, chicken pox or shingles; or you’ve injured your cornea.

Symptoms of corneal ulcer

Symptoms of a corneal ulcer include:

• A white spot on your cornea  
• Blurred vision 
• Pus or other discharge 
• Redness of the eye 
• Sensitivity to light 
• Severe pain and soreness of the eye 
• Swelling of the eyelids 
• Tearing 
• The feeling of having something in your eye

Diagnosis of corneal ulcer 

Your ophthalmologist will use a dye called fluorescein to show the damage to your cornea. They’ll also use an instrument called a slit lamp to examine your eye to determine whether you have a corneal ulcer.

Treatment of corneal ulcer

If your ophthalmologist determines that an infection is causing your corneal ulcer, they’ll prescribe antibiotic, antifungal or antiviral eye drops. You might be given antiviral or antifungal tablets, and you could have an injection of medication near your eye. Your ophthalmologist may also prescribe pain medication if your pain is severe.

Surgery to replace your cornea with a corneal transplant may be done if you have a badly damaged cornea.