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What is Glaucoma?

Glaucoma [glaw-KOH-muh] is the name for a group of diseases that can cause vision loss and blindness due to a damaged optic nerve. Having high eye pressure or high blood pressure can both lead to glaucoma. Some people can tolerate high eye pressure better than others, so it may or may not cause glaucoma in your eyes.

Glaucoma can also occur without increased eye pressure. The disease is more common for some groups of people, such as:

  • African Americans older than 40 years
  • Mexican Americans older than 60 years
  • Those who have a family history of glaucoma

The best way to find glaucoma is to visit an eye doctor and have a comprehensive eye exam. Eyedrops and other treatments can help prevent the onset of the condition. Regular eye visits are important because glaucoma may not initially have any symptoms. There may be no pain or loss of vision if the condition stays untreated. After more time passes, tunnel vision or a complete loss of vision may occur.

Glaucoma is different than other eye conditions like cataracts or macular degeneration. If you have cataracts, a thin film will develop over your cornea and make it harder to see. Macular degeneration is vision loss that occurs as you age, and your sharp central vision grows weaker. These conditions can all be diagnosed after an eye exam.

There are different types of glaucoma, including:

  • Open-angle glaucoma. This kind of glaucoma is the most common. It is often caused by high pressure in the eyes. People with this kind of glaucoma may get tunnel vision or even blindness in later stages.
  • Low-tension or normal-tension glaucoma. This type of glaucoma occurs even though the pressure in the eye is normal or low.
  • Angle-closure glaucoma. This is a medical emergency and occurs when fluid can’t get out of the eye. Without immediate treatment, the eye can go blind.
  • Pigmentary glaucoma. People with this kind of glaucoma have bits of pigment that build up and block the exit of fluid from your eye.
  • Secondary glaucoma. This condition can be caused by diabetes or high blood pressure that goes untreated or is treated poorly. Glaucoma may also develop with some kinds of eye tumors, or when the eye undergoes surgery.
  • Congenital glaucoma. This is a rare type of glaucoma that occurs in babies and young children. 


People with glaucoma may not experience any symptoms at first. There are different kinds of glaucoma. Open-angle glaucoma — the most common type of glaucoma — has these symptoms:

  • Blind spots in your side vision, or in your forward vision
  • Tunnel vision, when the condition grows more advanced

Another type of glaucoma, acute angle-closure glaucoma, has more serious symptoms that can include:

  • Severe headaches
  • Pain in the eyes
  • Nausea
  • Vomiting
  • Blurred vision
  • Redness in the eyes
  • Halos around lights
  • Eventual blindness

If you experience these symptoms you should get to the doctor as soon as possible.

Treatment is very successful at keeping glaucoma from getting worse. However, about 15 out of 100 people treated with the condition will become blind in at least one eye during the next 20 years.

When to See a Doctor

Go to an emergency department if you experience the symptoms of acute-angle glaucoma. See a doctor as soon as possible if you notice the symptoms of open-angle glaucoma.

Since glaucoma has so few symptoms, you should have regular check-ups with your eye doctor to ensure that you aren’t developing the condition. See an eye doctor at least once every 4 years if you are over the age of 40. Go every 2 years if you know you have a family history of the condition or are older than 65 years.

When you visit your eye doctor, some questions you may want to ask include:

  • Do I have any of the signs of glaucoma?
  • Are there any tests that I need to have to check for signs of glaucoma?
  • How serious is my condition? (If you already have a diagnosis)
  • How should I treat my glaucoma?

Is there anything I should avoid that could make it worse?


Glaucoma is caused by damage to the optic nerve at the back of your eye. Some causes include:

  • High blood pressure
  • High eye pressure
  • Damage to the optic nerve
  • Certain kinds of eye cancer
  • Fluid buildup in the eyes
  • Genetics
  • Complications following eye surgery
  • Other conditions like diabetes

Diagnosis and Tests

Glaucoma can be diagnosed using a variety of tests including:

  • Visual acuity test. In this test, your doctor will ask you to read letters on an eye chart to check your vision.
  • Dilated eye exam. Eye drops are placed in your eyes to make the pupils larger. A magnifying glass can then be used to look inside your eye and check for signs of damage.
  • Visual field test. This test checks your side vision for signs of vision loss.
  • Tonometry [toh-NOM-i-tree]. This test checks to see if the pressure in your eyes is normal.
  • Pachymetry [pa-KIM-i-tree]. This test measures your cornea to see how thick it is.


There is no cure for glaucoma, but treatment can slow the condition down and prevent further loss of vision. Treatment methods include:

  • Medicines. Medicines for glaucoma are given as eyedrops or taken by mouth. The eyedrops lower the pressure in the eyes, and the pills can help the eye make less fluid. This also lowers eye pressure. It’s important to keep taking these medicines even though you aren’t experiencing the symptoms of glaucoma.
  • Laser trabeculoplasty [tra-BEK-yoo-low-PLAS-tee]. This treatment helps get fluid out of your eye that’s causing too much pressure. This procedure is done at the eye clinic or at the doctor’s office. Laser surgery can help many people, but the good it does can wear off. You may need to schedule another procedure to keep the eye pressure down.
  • Surgery. Surgery can be done in an operating room to drain fluid from the eye and relieve pressure. This type of surgery may have some side effects, including cataracts, other cornea problems, or an eye infection. It works best if you haven’t had any other kind of eye surgery. The surgery is only done on one eye at a time.


You may not be able to prevent glaucoma, but these self-care tips can prevent the damage caused by the condition:

  • Have regular eye exams. This is the best way to prevent glaucoma from causing blindness. Regular eye exams can check for fluid buildup or high eye pressure. Eyedrops and medicines can prevent the condition from getting worse.
  • Get your family’s eye health history. Glaucoma often runs in families. If it runs in your family, you may need more frequent eye exams.
  • Exercise. Regular exercise may lower blood and eye pressure which will help protect your eyes.
  • Medicine. If you have been diagnosed with glaucoma, special eyedrops or other medicine can help. Glaucoma medicine needs to be used regularly even if you aren’t experiencing any symptoms.
  • Eye protection. Wear eye protection since eye injuries can lead to glaucoma.
Glaucoma is the name for a group of diseases that can cause vision loss and blindness if it isn’t caught and treated early. The diseases affect the optic nerve in the eye. People with glaucoma may not notice any initial symptoms, but over time will develop tunnel vision or go blind. To detect glaucoma early, it’s important to get a regular eye exam from your eye doctor.