A corneal ulcer is an open sore on the cornea. Corneal ulcers can occur at any age, and are typically the result of an untreated scratch, or injury to the cornea. There are many causes of corneal ulcers. Contact lens wearers have an increased risk if they do not adhere to strict regimens for the cleaning, handling, and disinfection of their lenses and cases. A corneal ulcer can also be caused by bacteria, or viral infections which may be visible to the naked eye in the form of a white patch on the cornea. Other symptoms can include pain, redness, blurred vision, excessive tearing, and sensitivity to light. If left untreated, corneal ulcers can lead to serious vision loss, and even loss of an eye. In order to treat corneal ulcers, it is important to determine the cause of the ulcer. In most cases, combinations of antibiotics and other medications will be given to fight the infection. If the corneal ulcer is severe enough, a cornea transplant may be necessary once the infection is sterilized. If you experience symptoms related to a corneal ulcer, speak with an eye care professional immediately.