What Causes HSV (Herpes Simplex Virus) Keratitis

At a glance

  • HSV (Herpes Simplex Virus) keratitis is an eye infection that can lead to serious eye complications, including scarring of the eye, and blindness when left untreated.
  • HSV (Herpes Simplex Virus) keratitis can affect individuals who wear contact lenses and those who do not wear them.

What is HSV (Herpes Simplex Virus) keratitis?

HSV (Herpes Simplex Virus) keratitis is an infection of the cornea (the clear dome that covers the colored part of the eye) that is caused by HSV. The infection usually heals without damaging the eye, but more severe infections can lead to scarring of the cornea or blindness. HSV keratitis is a major cause of blindness worldwide.

Herpes Simplex Virus illustration
HSV-1, the strain causing mouth cold sores, is the primary corneal infection cause.

HSV is only found in humans and is spread through direct contact with someone who is infected with the virus. Most HSV keratitis infections happen after another part of the body—most commonly the mouth—has already been infected by HSV. HSV keratitis is often the result of a "flare up" (reactivation) of the earlier infection.


Symptoms of HSV keratitis include:

  • Eye pain
  • Eye redness
  • Blurred vision
  • Sensitivity to light
  • Watery discharge

If you experience any of these symptoms, remove your contact lenses (if you wear them) and call your eye doctor immediately.

Prevention methods

HSV keratitis can lead to vision loss or blindness if left untreated. Maintain eye health while wearing contact lenses through proper daily habits and regular consultation with an eye doctor.

  • Wash hands thoroughly before touching eyes, especially with cold sores or herpes blisters
  • Only use prescribed or recommended eye drops by an eye doctor or health care provider

HSV keratitis is usually diagnosed based on a patient’s health history and eye exam results. Lab testing is not usually necessary, but certain lab tests may further help to confirm HSV-1.

HSV keratitis treatment usually involves medicine, including eye drops or antiviral medications taken by mouth. Surgery is rarely necessary but may be considered if scarring on the eye from HSV keratitis causes vision problems. Each case of HSV keratitis is unique, and an eye doctor should determine the best treatment for each patient. While some treatments can greatly lower the severity and recurrence of symptoms, there is no cure for HSV.

Understanding risk

People who have had HSV keratitis are at risk for recurrences of the same infection. For these people, wearing contact lenses may further increase the risk.

People most at risk for HSV-1 (but not necessarily HSV keratitis) are:

  • Female
  • Non-Hispanic black or Mexican American
  • Born outside the United States
  • Sexually active, or have had 3 or more lifetime sex partners