What to Know About Corneal Ulcers

Medically Reviewed By William C. Lloyd III, MD, FACS
Was this helpful?

A corneal ulcer is an open sore on the cornea. The cornea is a thin, clear layer on the front of the eye that allows the eye to let in light. Eye infections and diseases cause corneal ulcers. The ulcers are treatable but can cause complications if untreated. This information came, in part, from the American Academy of Ophthalmology (AAO).

This article will provide more information about corneal ulcers, what their symptoms are, how doctors diagnose and treat them, and the outlook for corneal ulcers. 

What is a corneal ulcer? 

closeup image of sunlight shining on brown eye
Martin Flores/EyeEm/Getty Images

The AAO notes that a corneal ulcer is also known as keratitis. Keratitis refers to inflammation of the cornea. 

The cornea is the dome-shaped layer that covers the front of the eye. The AAO compares the cornea to a glass watch cover because it lets light in and protects the eye. Specifically, the cornea covers the iris, the colored part of the eye, and the pupil, which is the black dot in the middle of the eye.  

Corneal ulcers can be serious without treatment. They can damage your eye, alter your vision, or even lead to blindness. Left untreated, the ulcer may involve the full thickness of the cornea, which can create a hole inside the eye. However, there are treatment options for corneal ulcers. 

A corneal ulcer is different from a corneal abrasion. A corneal abrasion is a scratch or small cut on the cornea. A corneal abrasion can develop into a corneal ulcer if the abrasion becomes infected. 

Medical professionals diagnose between 30,000 and 75,000 corneal ulcers every year in the United States, according to a 2021 research review. Additionally, about 12% of all cornea transplants they perform are to treat corneal ulcer damage. 

What are the symptoms of a corneal ulcer?

The symptoms of a corneal ulcer are: 

  • redness
  • pain that may be severe
  • sensation as though something is in your eye
  • increase in tears
  • discharge from the eye
  • blurry vision
  • light sensitivity
  • eyelid swelling
  • white spot on the eye from damage to the cornea

The infection requires aggressive treatment because it can reach a point when it permanently damages the cornea. This can lead to loss of vision. However, corneal ulcers are treatable with medications. Surgery may be necessary, too. 

When to contact a doctor

Anytime you experience severe eye pain or other symptoms, such as eye discharge, changes in your vision, or swelling in your eye, contact an eye doctor for an assessment. 

Additionally, if you wear contacts and experience the above symptoms, remove your contacts and schedule an appointment with your doctor for an eye exam. Your doctor can let you know when to wear the contacts again.

What does a corneal ulcer look like?

 A white spot on the eye is a sign of a corneal ulcer. It is due to swelling of the layers of the cornea and dead tissue.


This is a corneal ulcer stained with fluorescein.

Murray McGavin/Community Eye Health via Flickr


This image shows fluid buildup on the cornea, which is the clear covering over the eye.

P Vijayalakshmi/Community Eye Health via Flickr

What causes a corneal ulcer?

The most common cause of a corneal ulcer is an infection. Corneal ulcer causes include: 

  • herpes simplex virus, which causes cold sores
  • varicella virus, which causes chickenpox and shingles
  • bacterial, fungal, or amoebic infection of a cut or other eye injury
  • dry eye syndrome
  • eyelid disorders, such as Bell’s palsy, that can dry out the cornea
  • chronic inflammation associated with autoimmune conditions 

Factors that increase the likelihood of a corneal ulcer

A corneal ulcer may be more likely to develop in people with:

  • regular contact lens use
  • eye injury possibilities due to certain hobbies and working in agriculture
  • shingles, which is a reactivation of the chickenpox virus
  • cold sores or other recurrent herpes virus infections

Read about types of herpes infections here.

What are ways to prevent a corneal ulcer?

Wearing contact lenses is associated with a higher chance of keratitis and corneal ulcers, according to the Centers for Disease Control and Prevention (CDC). If you wear contacts, one of the best ways to reduce your chances of corneal problems is to practice contact lens hygiene:

  • Change and clean your contacts as directed. Ensure the lens cleaning and rinsing products are sterile and clear when using them. If not, the solution may be contaminated.
  • Do not swim while wearing your contacts, as this may introduce microorganisms.
  • Do not wear your contacts while sleeping, as this increases the chance of corneal abrasion.
  • Disinfect and store your contacts properly.

Here are other steps you can take to prevent corneal ulcers:

  • Use sterile saline and other eye drops.
  • Wear protective eyewear when doing yard work or other activities that could damage the eye.
  • Get regular vision checks with an optometrist or ophthalmologist, a physician who specializes in diagnosing and treating eye diseases and conditions.
  • Do not ignore eye pain or changes in your vision — contact a doctor right away.

How do doctors diagnose a corneal ulcer?

To diagnose a corneal ulcer, an eye doctor will use a special dye that sits on the surface of the eye, along with a machine called a slit lamp. This is a microscope that coats the surface of the eye.

The doctor will be able to see the corneal ulcer because the dye will highlight it under the lamp. They may also take a sample of the corneal tissue to confirm the cause of infection. 

How are corneal ulcers treated?

The treatment of the corneal ulcer will depend on what causes the ulcer and its severity.

Medications for corneal ulcer

There are different types of medication that can treat a corneal ulcer. These can include eye drops containing antibiotic, antifungal, or antiviral medication. There are also oral medications or medications that your doctor can inject near the eye.

The doctor may also prescribe steroid eye drops, which may help reduce swelling and inflammation. Only take steroid eye drops if your doctor prescribes them because some steroidal eye drops can worsen an infection.


For severe ulcers and scarring, an eye doctor may recommend surgery. This is a corneal transplant, which replaces a damaged cornea with a donor cornea.  

A corneal transplant takes place after clearing the initial infection and healing. A transplant can restore vision lost from scarring. An artificial cornea may be an option.

Home care for your eyes

It is important not to treat a corneal ulcer at home on your own. Always contact a doctor for eye pain, changes in vision, swelling, or discharge from your eye. 

However, after your eye doctor develops an appropriate plan of care with you, you can care for your eye(s) at home by:

  • taking all of your prescription medication
  • avoiding contact use
  • resting your eyes so they do not become overly dry 
  • wearing protective eye gear as necessary
  • telling your doctor if symptoms worsen or you develop new symptoms

What is the outlook?

With treatment, complete healing of a corneal ulcer can take several weeks. Recovery time depends on the cause and severity of infection. Your doctor will most likely schedule several follow-up visits to ensure the corneal ulcer heals properly and that there are no complications. Ask your doctor what to expect with healing and recovery.

Some conditions can make you more likely to have future corneal ulcers. For example, if the ulcer is due to an eyelid disorder or chronically dry eyes, you may need to take extra steps to prevent a corneal ulcer from reoccurring. 

If you wear contact lenses, this may mean less time wearing them. You also may need to contact your eye doctor more often or use medicated eye drops.

Other frequently asked questions

Here are some other questions people ask about corneal ulcers.

Can a corneal ulcer take months to heal?

Some corneal ulcers take several months to heal. In particular, corneal ulcers caused by the amoeba, Acanthamoeba, involve the use of medicated eye drops for “a number of months,” according to Merck Manual. People can also develop a chronic corneal ulcer that is resistant to treatment.

What helps corneal ulcers heal faster?

An eye doctor may prescribe steroid eye drops after treating the infection. Steroids are anti-inflammatories that may accelerate healing by reducing inflammation. Steroid eye drops may also reduce scarring, but there is some debate about this effect. In addition to taking the prescription antimicrobial medicine, you may be able to enhance the healing process by using cool compresses and resting your eye.

Can a corneal ulcer cause blurred vision?

Blurred vision is possible symptom of a corneal ulcer and other conditions, such as dry eye syndrome. Other symptoms of a corneal ulcer include eye redness, irritation, pain, and discharge.

Read up on dry eye syndrome here.


Corneal ulcers are open sores that develop on the top layer of the eye, usually as the result of an infection. Bacteria, viruses, fungi, and other microorganisms can cause the infection. Some people, including those who wear contact lenses, get cold sores, or work in hazardous occupations, may have a higher chance of developing corneal ulcers. 

Corneal ulcers can cause eye pain, redness, discharge, and vision changes. Treatment is typically straightforward and can prevent vision loss. This usually includes eye drops, pain relief medication, and steroids.

Severe corneal ulcers may require a corneal transplant, in which doctors place a new cornea onto the eye. In most cases, corneal ulcers are preventable. If you wear contacts, change them regularly and follow all recommended steps for cleaning and storing them to prevent an infection. 

Was this helpful?
Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2022 May 24
View All Eye Health Articles
THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.
  1. Boyd, K. (2021). Corneal abrasion and erosion. https://www.aao.org/eye-health/diseases/what-is-corneal-abrasion
  2. Byrd, L. B., et al. (2021). Corneal ulcer. https://www.ncbi.nlm.nih.gov/books/NBK539689/
  3. Corneal conditions. (2019). https://www.nei.nih.gov/learn-about-eye-health/eye-conditions-and-diseases/corneal-conditions
  4. Healthy contact lens wear and care. (2021). https://www.cdc.gov/contactlenses/index.html
  5. Lazreg, S., et al. (2020). Fast and sustained healing of resistant corneal ulcers using corneal scrubbing and matrix regenerating therapy [Abstract]. https://journals.sagepub.com/doi/10.1177/1120672120921379?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%20%200pubmed
  6. Roat, M. I. (2020). Corneal ulcer. https://www.merckmanuals.com/professional/eye-disorders/corneal-disorders/corneal-ulcer
  7. Turbert, D. (2022). What is a corneal ulcer? https://www.aao.org/eye-health/diseases/corneal-ulcer