A corneal ulcer is an open sore on the eye’s cornea—the tough, transparent membrane that covers and protects the pupil and iris (colored portion). Corneal ulcers are typically very painful—especially when caused by a bacterial infection—and feel as if something is intractably lodged in the eye even if no foreign object is visible upon close inspection.

A simple abrasion on the surface of the cornea produces the same sort of pain, but this usually subsides within 48 hours. If pain persists longer, chances are great that some type of infection has set in, causing an ulceration, which requires immediate treatment. If neglected, corneal ulcers may scar the cornea, resulting in permanent vision impairment. In rare cases the infection may penetrate the cornea to involve other structures of the eye, requiring emergency surgery.

What Causes Corneal Ulcers?

  • Corneal ulcers most often originate as a corneal abrasion (due to a scratch from a tiny fleck of steel, glass, dirt, or dust) that then becomes infected with bacteria or, rarely, fungi, or protozoans like amoebae. Viral corneal ulcers are most often due to infection with the herpes simplex virus rather than trauma.
  • Contact lens wearers (especially overnight users) and chronically ill or debilitated patients are more prone to corneal ulcers.
  • Eye surgery or preexisting corneal disease may increase the likelihood of corneal ulceration.
  • Mechanical or chemical trauma may be causes.
  • Hyperthyroidism (Graves’ disease) or other conditions affecting the structure or function of the eyelids can cause corneal ulcers.
  • Other causes of corneal ulcer include Bell’s palsy (this condition often prevents the eyelid from closing all the way), severely dry eyes, severe allergies and inflammatory disorders.

Symptoms of Corneal Ulcers

  • Severe eye pain, feeling that something is lodged in the eye (foreign body sensation)
  • Redness in or discharge from the eyes
  • Heightened sensitivity to light (photophobia); aversion to bright light
  • Excessive tearing
  • Blurred vision
  • Eyelid spasms
  • Visible white, gray, or yellow ulceration on the cornea
  • Thinning of the cornea
  • Hypopyon (collection of white blood cells in the anterior chamber of the eye)
  • Swelling of the upper eyelid

Prevent Corneal Ulcers

  • If you wear contact lenses, remove and clean them daily (or as recommended by the manufacturer or an eye care professional). Do not clean them with saliva or tap water.
  • Wear protective goggles when warranted (at a workbench, for example); wear sunglasses outdoors on windy days.
  • Wash hands frequently and keep your fingers away from your eyes if you have cold sores.

Corneal Ulcers Diagnosis

  • Physical examination by an ophthalmologist is usually all that is required to diagnose a corneal ulcer.
  • A swab culture of the ulcer or, if necessary, a biopsy (tissue sample) will be obtained to identify the infectious organism.

How Corneal Ulcers Are Treated

  • Corneal ulcers caused by bacterial infections are treated with antibiotic eyedrops or ointments.
  • Viral ulcers may be treated with antiviral drops or pills. Further ulcers may occur, however, in cases where the infection is persistent, such as those caused by the herpes simplex virus.
  • Fungal or amoebic corneal ulcers are treated with an appropriate drug.
  • Topical corticosteroid drops may be prescribed in some cases to reduce inflammation, once the infection has been adequately controlled with antibiotics.
  • Severe cases that result in corneal scarring may warrant corneal transplant.
  • Any underlying eye disorder is also treated.

When to Call a Doctor

  • See an ophthalmologist right away for any eye pain that persists for more than several hours. If you are wearing contact lenses, remove them at once.


Johns Hopkins Symptoms and Remedies: The Complete Home Medical Reference

Simeon Margolis, M.D., Ph.D., Medical Editor

Prepared by the Editors of The Johns Hopkins Medical Letter: Health After 50

Updated by Remedy Health Media

Publication Review By: the Editorial Staff at Healthcommunities.com

Published: 16 Nov 2011

Last Modified: 16 Dec 2014