Herpes keratitis is a viral infection of the eye caused by the herpes simplex virus (HSV). There are two major types of the virus. Type I is the most common and primarily infects the face, causing the familiar “cold sore” or “fever blister.” Type II is the sexually transmitted form of herpes, infecting the genitals.

While both kinds of herpes can spread to the eye and cause infection, Type I is by far the most frequent cause of such infections. Infection can be transferred to the eye by touching an active lesion (a cold sore or blister) and then your eye. The symptoms of herpes keratitis may include:

• Pain
• Redness
• Blurred vision
• Tearing
• Discharge
• Sensitivity to light

Symptoms and Treatment

Type I herpes is very contagious and commonly is transmitted by skin contact with someone who has the virus. Almost everyone — about 90 percent of the population — is exposed to Type I herpes, usually during childhood. After the original infection, the virus lies in a dormant state, living in nerve cells of the skin or eye. Reactivation can be triggered in a number of ways, including:

• Stress
• Sun exposure
• Fever
• Trauma to the body (such as injury or surgery)
• Menstruation
• Certain medications

Once herpes simplex is present in the eye, it typically infects the eyelids, conjunctiva (the thin, filmy mucous membrane that covers the inside of the eyelids and the white part of the eye) and cornea (the clear, front window of the eye). Signs and symptoms of the infection include:

• Red eye
• Eye pain or soreness
• Tearing
• Light sensitivity
• Irritation
• Blurred vision

If the infection is superficial, with ulcers involving only the cornea’s top layer (called the epithelium), it will usually heal without scarring. However, it if involves the deeper layers of cornea (which can happen after time), the infection may lead to scarring of the cornea, loss of vision and sometimes even blindness. Left untreated, herpes keratitis can severely damage your eye.

Treatment of the infection will depend on its severity. Mild infection is typically treated with topical and sometimes oral antiviral medication. Your ophthalmologist (Eye M.D.) may gently scrape the affected area of the cornea to remove the diseased cells. In case of severe scarring and vision loss, a corneal transplant may be required.

It is very important to consult an ophthalmologist before beginning any treatment, because some medications or eyedrops may actually make the infection worse.

There is no complete cure for herpes; once the virus is in the body, you cannot get rid of it. However, there are some things you can do to help control recurring outbreaks:

• If you have an active cold sore or blister, avoid touching your eyes.
• Avoid over-the-counter steroid eyedrops, as these cause the virus to multiply.
• Stop wearing contact lenses if you keep having multiple reoccurrences.
• See an ophthalmologist immediately if symptoms of ocular herpes begin to return.

Last reviewed and updated in January 2009,
by the American Academy of Ophthalmology.