A corneal ulcer is an open sore on the cornea, the clear front surface of the eye. It is often caused by an infection. Wearing contact lenses, especially sleeping in them, raises the risk. Symptoms can include eye pain, redness, a feeling that something is in the eye, watering, pus or other discharge, blurred vision, sensitivity to light, swollen eyelids and sometimes a white spot on the cornea. A corneal ulcer is a medical emergency. If you notice these symptoms, especially if you wear contact lenses, see an eye doctor the same day. If you have severe eye pain with redness, or your vision suddenly gets worse, go to the nearest emergency department straight away or call 108 or 112. Prompt treatment lowers the risk of lasting damage to your vision.
General health information, not a diagnosis. Reviewed and updated by Chetna Hospital’s content team with the help of AI writing tools, November 2026.
