With all the protective eyewear warnings centered around the August 21 eclipse last year, you might have thought one of the leading causes of blindness is looking directly at the sun. It’s not.

One of the leading causes of blindness is glaucoma when left untreated. The key here is left untreated. According to The Eye Diseases Prevalence Research Group, it’s estimated that more than 3 million Americans have glaucoma, but only half of them know they have it. There’s a reason, after all, that the disease was nicknamed “the silent thief of sight.”

When the eye disease is diagnosed during a complete eye exam, your eyesight can be protected and saved. Don’t wait for symptoms to develop. The most important message here is that severe glaucoma-related vision loss can be prevented.

What is Glaucoma?

Glaucoma (glaw-koh-muh) is a disease that damages your eye’s optic nerve, made up of nerve fibers that carry images to the brain. The most common type of glaucoma is open-angle. It develops when clear fluids leave the eye’s anterior chambers too slowly through the drainage canals, causing a fluid build-up—like a clogged drain. This build-up increases eye pressure, causing damage to the optic nerve.

This form of glaucoma can be tricky to diagnose without a complete eye exam: there’s no pain and no symptoms. Vision loss begins gradually with peripheral or side vision. People especially at risk of getting glaucoma include anyone over the age of 60 (for African Americans, the increase in risk begins after age 40), anyone with a family history of glaucoma, anyone who has suffered a serious eye injury, and those with diabetes and poor blood circulation. It can happen, though, to anyone. Case in point: Bono, the lead singer of the popular music group U2, wears tinted sunglasses not as a fashion statement, but because he was diagnosed with glaucoma when he was in his 30s. (The tinted sunglasses help protect his eyes from light sensitivity when he’s on stage.) He’s proof that glaucoma doesn’t discriminate; even babies can be born with it. He’s also proof that—when treated before there’s damage to the optic nerve—your vision can be saved.

Another type of glaucoma is closed or narrow angle glaucoma. This can occur when the iris of the eye is too close to the drainage angle. According to the American Academy of Ophthalmology (AAO), a good way of visualizing this type of glaucoma is “like a piece of paper sliding over a sink drain.” When drainage is blocked, it can result in an acute attack.

Signs of acute angle-closure glaucoma attack:

• Blurry vision
• Severe eye pain
• Headache
• Nausea
• Vomiting
• Rainbow-colored rings or halos around lights

This type of glaucoma can be very serious. If you don’t call your eye doctor immediately, you could lose your vision.

Treatment Options

If you’re diagnosed with glaucoma, there are ways to control the disease. One option is by using daily eye drop medicine, reducing the pressure. Laser surgery is another option for treating glaucoma, done in the ophthalmologist’s office or an outpatient surgery center; and a third option is surgery done in a hospital with an eye surgeon. The good news is that the disease can be managed. Every day, researchers are making new discoveries and providing people with help and hope.

FAST FACTS:

• Glaucoma can occur in one or both eyes.
• There is no cure.
• Damage is irreversible.
• You can’t prevent glaucoma, but you can slow its development with proper treatment.
• Those most at risk are people over 60—for African Americans, the increase in risk begins after age 40.
• The risk of developing glaucoma increases slightly with each year of age.
• Other risk factors include family history, suffering severe trauma to the eye, and certain medical conditions, including diabetes.
• Chances are high that you won’t go blind if you take your medication correctly and schedule follow-up eye exams.
• The best help loved ones can give is emotional support.

During the month of January, take the time to schedule an eye exam. For more information about glaucoma, visit the National Eye Institute website.