honeypot link

Merck Manual

Please confirm that you are not located inside the Russian Federation

Quick Facts

Corneal Ulcer


The Manual's Editorial Staff

Last full review/revision Jun 2020| Content last modified Jun 2020
Click here for the Professional Version
Get the full details
Topic Resources

What is a corneal ulcer?

Your cornea is the clear layer at the front of your eye.

An ulcer is a deep sore. So, a corneal ulcer is a deep sore on your cornea.

An Inside Look at the Eye

An Inside Look at the Eye
  • Corneal ulcers are usually caused by infection

  • The infection may start with an eye injury or scratch, irritation from a contact lens, or certain eye diseases

  • You may have eye pain, tears, sensitivity to light, and red, bloodshot eyes

  • Doctors usually treat corneal ulcers with antibiotic eye drops

  • Sometimes after a corneal ulcer heals, your cornea has a cloudy scar that affects your vision

See a doctor right away if you think you have a corneal ulcer because it can lead to blindness.

What causes corneal ulcers?

Most corneal ulcers are caused by:

  • Infection

Usually, you also have an eye problem that makes infection more likely, for example:

What are the symptoms of a corneal ulcer?

Usually, a corneal ulcer develops in only one eye.

Symptoms of a corneal ulcer include:

  • Red, watery, bloodshot eye

  • Eye pain

  • Feeling like you have something in your eye

  • Light hurts your eye

  • A white or grayish spot on your eye

If a corneal ulcer isn't treated, it can go deeper, and the infection can damage other parts of your eye.

Sometimes you have a scar after a corneal ulcer heals. The scar can affect your vision.

How can doctors tell if I have a corneal ulcer?

Doctors diagnose a corneal ulcer by looking at your eye. They'll do a full eye exam, including checking your vision, and may also:

  • Scrape off a sample of the corneal ulcer for testing

How do doctors treat corneal ulcers?

A corneal ulcer can lead to blindness, so it is important to see a doctor right away if you think you may have a corneal ulcer.

Doctors will treat you right away with:

  • Antibiotic eye drops to fight infection

  • Eye drops to dilate your eye, which helps with the pain

You may need to use the antibiotic eye drops every hour or two at first.

Rarely, if a scar affects your vision, doctors may do a corneal transplant (an operation to take out your cloudy cornea and replace it with a healthy, clear one).

NOTE: This is the Consumer Version. DOCTORS: Click here for the Professional Version
Click here for the Professional Version
Others also read

Also of Interest