What causes herpes eye disease?

Herpes simplex virus (HSV) type 1 most often causes herpes eye disease. HSV type 2 rarely causes eye symptoms. It more often causes genital herpes infections.

If you have herpes eye disease, it means you were infected by HSV at some point. When it happened, you likely did not have any symptoms. But once the herpes virus is in your body, it stays there for life. It is often in a dormant state. This means it does not always cause any problems or symptoms. But sometimes the virus will become active and cause symptoms. This often happens in one set of nerves. If nerves to your eye are affected, symptoms of herpes eye disease can occur.

How herpes affects the eye

Most people infected with the herpes virus have no symptoms. Or they may have mild symptoms such as a cold sore around the mouth that spreads to the eye. If the virus grows and becomes active, herpes eye disease can occur. Herpes eye disease can affect and damage different parts of your eye, including your:

• Eyelids

• The clear layer on the front of your eye (cornea)

• The thin layer covering the inside of your eyelids and the white part of your eye (conjunctiva)

Less commonly it can also affect:

• The light-sensitive part of the back of the eye (retina)

• The white part of your eye (sclera)

• The colored ring on the front of your eye (iris)

Symptoms of herpes eye disease

Symptoms of herpes eye disease can include:

• Eye redness

• Eye pain

• Tearing

• Sensitivity to light

• Headache

• Feeling like there is something in your eye

• Rash with blisters on the eyelids

• Painful sore on eyelid or eye

• Blurred vision

• Vision loss

Repeated flare-ups of herpes eye disease can scar your cornea. This scarring may be long-lasting (permanent). This can lead to loss of eyesight and even blindness.

What can trigger a herpes eye disease flare-up?

You may only have a single flare-up of the virus. But the virus may become active and cause symptoms again. This is common. Certain things can trigger a flare up, such as:

• Illness

• Stress

• Sunlight

• Eye injury

• Having your period

• Using steroid medicine

Diagnosing herpes eye disease

Your eye care doctor (ophthalmologist) will ask about your health history and give you an eye exam. They may look into your eye with a slit lamp microscope. This is a device that magnifies the surface and inside of your eye. Your doctor may also put a dye into your eye. This lets them look at your cornea. In rare cases, a tiny bit of your eye tissue may be sent to a lab. This is done to test for the virus.