Glaucoma is a group of eye conditions that can cause vision loss and blindness by damaging a nerve in the back of your eye called the optic nerve.

The symptoms can start so slowly that you may not notice them. The only way to find out if you have glaucoma is to have a comprehensive eye exam.

There is no cure for glaucoma, but early treatment can often stop the damage and protect your vision.

There are many different types of glaucoma, but the most common type in the United States is called open-angle glaucoma - that's what most people mean when they talk about glaucoma. Other types of glaucoma are less common, such as angle-closure glaucoma and congenital glaucoma.

Glaucoma usually has no symptoms at first. That's why half of people with glaucoma don't even know they have it.

Over time, you may slowly lose your vision, usually starting with your side vision (peripheral) - especially the part of your vision closest to your nose. Because it happens so slowly, many people cannot say that their vision is changing, especially in the beginning.

But as the disease gets worse, you may find that you can't see things to the side. Without treatment, glaucoma can eventually cause blindness.

Anyone can get glaucoma, but some people are at higher risk. You're at higher risk if you:

• Are over 60

• Are African American or Hispanic / Latino and over 40

• Have a family history of glaucoma

Talk to your doctor about your risk of glaucoma and how often you should get checked out.

Scientists aren't sure what causes the most common types of glaucoma, but many people with glaucoma have high eye pressure (intraocular pressure) - and treatments that lower eye pressure help slow the disease.

There is no way to prevent glaucoma. That's why eye exams are so important - so you and your doctor can find it before it affects your vision.

Ophthalmologists can check for glaucoma as part of a comprehensive dilated eye exam. The exam is simple and painless - your doctor will give you a few eye drops to dilate (dilate) your pupil and then check your eyes for glaucoma and other eye problems. The exam includes a visual field test to check your peripheral (side) vision.

Doctors use a few different types of treatment for glaucoma, including medications (usually eye drops), laser treatment, and surgery.

If you have glaucoma, it is important to start treatment right away. While it won't reverse your vision, treatment can keep it from getting worse.

Discuss your options with your doctor. Although glaucoma is a serious disease, the treatment works well. Remember these tips:

• If your doctor prescribes medication for you, take it every day

• Tell your doctor if your treatment causes side effects

• Consult your doctor for regular check-ups

• If you have trouble with everyday activities because of your vision loss, ask your doctor about low vision services or devices that can help

• Encourage family members to get checked for glaucoma, as it can run in families