What Are Corneal Ulcers?

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A corneal ulcer is an erosion or open sore on the surface of the cornea. The cornea is the transparent area at the front part of the eye that serves as a window through which we see. It also refracts light and offers protection to other parts of the eye. If the cornea becomes inflamed due to infection or injury, an ulcer may develop.

A corneal ulcer is a serious condition that must be treated promptly to avoid lasting vision problems. Though good medicines are available for treatment, corneal ulcers can cause severe loss of vision and even blindness.

Doctor Examining Patient's Eye With a Occluder
Digital Vision/Photodisc/Getty Images

Corneal Ulcer Symptoms

Symptoms of a corneal ulcer are usually obvious, especially if the ulcer is deep. Because the cornea is very sensitive, corneal ulcers tend to produce severe pain. Vision is sometimes impaired, and the eye may be tearing and red. It may also hurt to look at bright lights.

If you have any of the following symptoms, you should be checked by an eye practitioner right away:

  • Redness
  • Pain
  • Tearing
  • Discharge
  • White spot on the cornea
  • Blurry vision
  • Itching
  • Light sensitivity


Corneal ulcers are most commonly caused by germs. Although the human eye is well-protected by the eyelid and abundant tears, germs and bacteria may be able to enter the cornea through small abrasions if it is damaged.

Corneal ulcers are common in people who wear contact lenses, especially if they are worn overnight. In fact, your risk of ulcers increases tenfold when using extended-wear soft contacts.

Generally, the deeper the corneal ulcer, the more serious the condition becomes. A very deep ulcer can cause scarring on the cornea, blocking light from entering the eye.

Common causes of corneal ulcers include the following:

  • Bacteria
  • Viruses
  • Injury
  • Severe allergic disease
  • Fungi
  • Amoebas
  • Inadequate eyelid closure

Risk factors of corneal ulcers include:

  • Contact lens wearers
  • People with cold sores, chickenpox, or shingles
  • People who use steroid eye drops
  • People with dry eye syndrome
  • People with eyelid disorders that prevent proper functioning of the eyelid
  • People who injure or burn their cornea


Early diagnosis is important in treating corneal ulcers. Your healthcare provider will ask questions to determine the cause of the ulcer.

Your eyes will then need to be examined under a special bio-microscope called a slit lamp. The slit-lamp exam will allow your practitioner to see the damage to your cornea and determine if you have a corneal ulcer. A special dye, called fluorescein, will be placed into your eye to light up the area and aid in the diagnosis.

If it is not clear what the exact cause is, your medical professional may take a tiny tissue sample, or culture, of the ulcer in order to know how properly treat it. After numbing your eye with special eye drops, cells may be gently scraped from the corneal surface so that they can be tested.


Treatment for corneal ulcers needs to be aggressive, as some ulcers lead to vision loss and blindness. Treatment usually involves antibiotics as well as antiviral or antifungal medications.

Steroid eye drops may also be given to reduce inflammation. However, it is important that steroids can cause glaucoma and cataracts and should be taken as directed. Steroids can also make a viral cause worse. It is very important to follow proper instructions from your healthcare provider for how to used steroids safely.

Some healthcare providers prescribe topical eye drops to be used several times per day until the ulcer is completely healed. In severe cases, patients are hospitalized so that the correct treatment is given.

Certain supplements, such as vitamin C, may be prescribed to lessen corneal scarring. If an ulcer not healing normally with typical treatment, an amniotic membrane will be placed on the cornea for seven to 10 days. 

When to Call a Healthcare Provider

Call your healthcare provider right away if you have:

  • Severe or persistent eye pain and redness
  • Persistent discharge from the eye
  • Blurry vision developing suddenly

If a severe infection causes permanent scarring, a corneal transplant may be needed to restore vision. In such instances, blindness or the total loss of the eye may occur if treatment is delayed.

6 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Turbert D. What is a corneal ulcer (keratitis)? American Academy of Ophthalmology.

  2. AAO Quality of Care Secretariat, Hoskins Center for Quality Eye Care. Extended wear of contact lenses - 2013. American Academy of Ophthamology.

  3. Kellogg Eye Center. Keratitis (corneal ulcers).

  4. Wilson SL, El Haj AJ, Yang Y. Control of scar tissue formation in the cornea: strategies in clinical and corneal tissue engineeringJ Funct Biomater. 2012;3(3):642-687. doi:10.3390/jfb3030642

  5. MedlinePlus. Corneal ulcers and infections.

  6. Weiner G. Corneal perforations. American Academy of Ophthalmology.

By Troy Bedinghaus, OD
Troy L. Bedinghaus, OD, board-certified optometric physician, owns Lakewood Family Eye Care in Florida. He is an active member of the American Optometric Association.