• Mayo Clinic Minute: What are eye shingles?

Shingles is caused by the varicella-zoster virus — the same virus that causes chickenpox. If you've had chickenpox, the virus can lie dormant in your body's nerve tissue for years when suddenly it's triggered by stress or a weakened immune system, and manifests as shingles. A new shingles vaccine called Shingrix is recommended for anyone over 50. It helps prevent the disease and reduces the severity of symptoms.

Ophthalmic shingles is one particular version of the disease that can have some serious side effects that ultimately can cause permanent damage to your vision.

Watch: The Mayo Clinic Minute

Journalists: Broadcast-quality video (0:59) is in the downloads at the end of this post. Please "Courtesy: Mayo Clinic News Network." Read the script.

You're probably familiar with shingles, a viral infection that causes a painful rash — usually on the body's torso. But did you know that shingles also can affect the eye?

"Shingles around the eye typically involves the skin of the forehead and the skin of the upper lid. It can also involve the side of the nose or the tip of the nose," says Dr. Keith Baratz, a Mayo Clinic ophthalmologist.

The virus lies dormant for years, but, when triggered by stress or a weakened immune system, it travels along nerve pathways to the skin and usually affects only one side of the face.

"You can almost draw a line right down the middle of the forehead when you get the rash," says Dr. Baratz.

In addition to the telltale rash or blisters, patients often will have pink eye, swelling or even blurry vision.

"It can be very painful. But when it’s around the eye, it’s really a dangerous problem. The complications in the eye can last for a long time," says Dr. Baratz. "So it needs to be considered very, very seriously."

The key to overcoming eye shingles is quick diagnosis and aggressive treatment with antiviral medication. Your doctor will perform several dilated eye exams to monitor the health of your eye until the shingles are resolved.