What is eye herpes?

Eye herpes, also known as ocular herpes, is a group of eye problems caused by a herpes simplex virus (HSV). Most of the time, eye herpes is caused by the same virus that gives you cold sores on your mouth. It's called herpes simplex virus type 1, or HSV-1 for short.

More than half of Americans have type 1 herpes, but it rarely affects the eyes. Herpes simplex only causes eye symptoms in around 1 in 100 people who carry the virus.

Eye herpes can affect different parts of your eye and the area around it. Most people only have symptoms in one eye. 

A herpes simplex infection lasts your entire life, but the virus is asleep (dormant) most of the time. It can cause uncomfortable symptoms when it wakes up (reactivates) once in a while.

You may feel little to no discomfort the first time you have eye herpes. Some people don't notice symptoms until their infection returns several times.

Sometimes, eye herpes damages the eye in ways that can lead to other problems in the future. Eye doctors can help manage these conditions so they don't hurt your vision.

Symptoms of eye herpes

Eye herpes, or ocular herpes, symptoms usually only happen in one eye, but some people have symptoms in both eyes. Your symptoms can vary depending on which parts of your eye are affected.

Eye herpes can cause one or more of these symptoms:

• A red eye
• Eye pain
• A feeling like something is stuck in your eye
• Blurry vision
• A teary or watery eye
• Light sensitivity
• A swollen eyelid
• Small blisters around your eye

A deeper infection could cause:

• Halos around lights
• Vision loss
• Sensitivity to light

Talk to an eye doctor right away if you have severe symptoms or sudden eyesight changes.

Eye herpes causes

When doctors talk about eye herpes, they're usually talking about eye problems caused by type 1 of the herpes simplex virus.

A type 1 herpes infection is lifelong, but the virus is usually asleep. When it wakes up, it usually only causes a cold sore on the lips or around the mouth (oral herpes).

Researchers think eye herpes can happen one of two ways:

• An infected fluid touches your eye
• The virus travels from your mouth to your eye through a nerve inside your head

Herpes simplex virus type 2 (HSV-2) can affect your eyes, too, but it's rare. Type 2 may also cause oral herpes sometimes.

But type 2 herpes usually causes the sexually transmitted disease (STD) genital herpes. Type 1 can also cause genital herpes.

Other forms of the virus

Other viruses in the herpes family can cause separate eye conditions:

• Varicella-zoster virus – The virus that causes chickenpox. If the virus wakes up later in life, it can cause shingles. This can lead to an eye condition called herpes zoster ophthalmicus.
• Cytomegalovirus – A virus that can cause an eye condition called cytomegalovirus retinitis in people with a weakened immune system.
• Epstein-Barr virus – Well-known for causing infectious mononucleosis — more often called "mono." It can rarely cause serious problems like retinal vasculitis.

Types of herpes keratitis

Keratitis is when the cornea is inflamed from an infection, injury or another condition.

The cornea is the clear dome that covers the front of each eye. All the light you see has to pass through the cornea first.

With an early diagnosis, mild herpes keratitis can be treated without damaging your cornea. More severe infections may affect your eyesight.

An eye doctor can diagnose your specific condition and tell you how to treat it.

Epithelial keratitis

Epithelial keratitis is the most common type of eye herpes. It affects as many as 4 out of 5 people who have a herpes eye infection.

Epithelial keratitis is inflammation in the outer layer of your cornea. With treatment, it usually heals without leaving scars.

Stromal keratitis

Around 1 in 5 people with eye herpes have stromal keratitis.

This form can be more serious since it affects a deeper layer of the cornea. It can cause extra blood vessel growth on your cornea (corneal neovascularization). This makes it more likely to cause corneal scars that can lead to vision problems.

Endotheliitis

Less commonly, eye herpes can affect the deepest layer of the cornea. This is called endotheliitis.

Endotheliitis can lead to chronic corneal edema and increased eye pressure, along with other problems. Without treatment, some of these issues can lead to vision loss.

Other conditions

Herpes simplex can cause problems inside your eye, too. This isn't common.

When the virus leads to inflammation in the colored part of your eye, it's known as herpes simplex iritis.

Herpes viruses can also damage the retina, the light-sensing layer of cells inside each eye. This condition, called necrotizing herpetic retinitis, is an emergency.

See an eye doctor right away if you notice eye floaters, light sensitivity and worsening vision in one eye. Some people will also have eye pain.

Preventing ocular herpes

The only proven way to prevent herpes on your eye is to avoid a herpes simplex infection. But that can be hard or impossible for many.

People who already carry the virus may be able to avoid flare-ups by limiting stress, sun exposure and other triggers as much as they can.

Wash your hands regularly and try not to touch your eyes if you or someone close to you has a cold sore or ocular herpes.

Risk factors

Someone who has never had a herpes infection can only get eye herpes when they come into contact with a fluid or surface infected with a herpes simplex virus.

Most people get first-time infections from someone who has at least one active herpes blister (like a cold sore) on their skin. Less often, you can also get infected by someone whose skin looks normal.

Once someone is already infected, certain things could trigger the virus to wake up again.

These triggers could include:

• Stress
• Exposure to UV light, either natural (like sunlight) or artificial (like tanning beds)
• Heat
• A fever
• Another illness or injury
• A weakened immune system
• Menstruation
• COVID-19 infection or vaccination
• Certain medicines

Sometimes, doctors don't know why the virus reactivates.

Eye herpes treatment

If you have herpes in your eye, you should talk to an eye doctor as soon as you can. Early treatment may stop your infection from getting worse.

Your eye doctor may give you antiviral medicine to help fight the infection. It can be taken by mouth, applied with eye drops or both.

Certain antiviral medications are more effective against eye herpes. These include drugs like:

• Acyclovir
• Valacyclovir
• Famciclovir
• Ganciclovir

Like oral herpes, ocular herpes symptoms can come back after they go away. To lower your risk, your doctor might suggest:

• Wearing glasses instead of contacts
• Washing your hands more often
• Not touching your eyes or the areas around them anytime you have a cold sore
• Avoiding certain steroid medications when possible
• Taking long-term, low-dose antiviral medicine

Eye herpes sometimes leads to other serious eye problems, even after a flare-up goes away.

One of these conditions is called neurotrophic keratitis. It can happen after herpes keratitis damages the sensitive nerves in your cornea.

An eye doctor can help you manage any reoccurring symptoms to protect your eye health.

A corneal transplant may be needed if the cornea is damaged and it affects your eyesight. Ophthalmologists use this procedure to help people see clearly again.

When to see an eye doctor

Eye herpes needs to be treated quickly so it doesn't get worse. Without treatment, it could permanently damage your vision.

If you think you have eye herpes, talk to an eye doctor as soon as you can. Don't try to treat the problem on your own.

Your doctor can make an accurate diagnosis and, if needed, help you treat and manage your condition.