What is glaucoma?

Glaucoma is an eye disease that may cause loss of vision. It usually happens when fluid builds up in the eye, causing an increase in pressure. This damages the eye’s optic nerve. People with glaucoma start slowly losing their peripheral (side) vision. Without treatment, they may lose their vision completely.


At first, glaucoma has no symptoms. It causes no pain and your vision is normal. Eventually, without treatment, you will start losing your peripheral vision. You might miss seeing objects out of the corner of your eye. Over time, it will seem like you are looking through a tunnel. If your glaucoma is left untreated, your vision may gradually decrease until it is gone completely.

Many people who have glaucoma are not aware they have the disease. By the time they notice loss of vision, the eye damage is severe.

Rarely, an individual will have an acute (sudden or short-term) attack of glaucoma. In these cases, the eye becomes red and extremely painful. Nausea, vomiting, and blurred vision may also occur. This is an eye emergency. Call your eye care professional right away if you experience these symptoms.

Causes & Risk Factors

What causes glaucoma?

Normally, fluid in your eye nourishes the eye and keeps it healthy. After the fluid circulates through the eye, it empties through a drain in the front of your eye. In people who have glaucoma, the fluid doesn’t drain properly. Instead, it builds up and causes increased pressure in the eye. This pressure damages the optic nerve and causes vision loss.

Who gets glaucoma?

Risk factors for glaucoma include:

  • Being 40 years of age or older.
  • Belonging to certain ethnic groups, including black and Latino.
  • A family history of glaucoma.
  • High pressure in the eyes.
  • Diabetes.
  • Hypertension
  • Heart disease.
  • Near-sightedness (it is difficult for you to see objects in the distance).


How is glaucoma diagnosed?

Glaucoma is usually diagnosed by an optometrist or ophthalmologist. These are people specially trained to provide care for the eyes. They will give you a comprehensive eye exam, which will include several tests. These tests include:

  • Visual acuity test – measures how well you see at different distances.
  • Visual field test – measures your peripheral vision.
  • Dilated eye exam – allows your eye care professional to examine your retina and optic nerve for signs of damage or other eye problems.
  • Tonometry – measures the pressure inside the eye.
  • Pachymetry – measures the thickness of your cornea.

Many of these tests can be used to diagnose glaucoma.


Can glaucoma be prevented or avoided?

There’s nothing you can do to avoid getting glaucoma. But you can prevent it from having a large impact on your vision. The best way to do this is by getting your eyes checked regularly. It is important to get comprehensive eye exams by an optometrist or ophthalmologist. Early diagnosis and treatment of glaucoma can prevent damage to the eye’s nerve cells and prevent severe vision loss.

People 18 to 60 years of age should have an eye exam every 2 years. After age 60, you should have an eye exam once a year.


The purpose of treatment is to lower the pressure in the eye. This will prevent further nerve damage and vision loss. Glaucoma is usually treated with medicated eye drops. Medicines that can be taken orally (in pill form) can sometimes be prescribed, as well.

It is important to take glaucoma medicines regularly, as prescribed by your eye care professional.  Because glaucoma doesn’t cause symptoms, you might forget to take your medicine. But you need to use the drops or pills regularly to help control the pressure in your eye.

When eye drops don’t help relieve pressure, you may need other treatment. Laser treatment uses a laser to open up the drain where fluid flows out. It is a painless procedure. If that doesn’t work, you may need surgery to create a new channel where fluid can flow out of your eye.

Everyday living

If your glaucoma was caught and treated early, you might not notice any difference in your vision. You can lead a normal life with no symptoms, as long as you take your medicine every day. If you are taking medicine for glaucoma, your eye care professional will likely want to see you regularly. This could be every 3 to 6 months.

If you have experienced some loss in your vision, talk to your eye care professional. There may be some low-vision services or devices that can help you make the most of your remaining vision. Community agencies could offer counseling, training, or other special services for people who have visual impairments.

Questions to Ask Your Doctor

  • What is the right treatment for me?
  • Will I have to continue my treatment for the rest of my life?
  • Does this treatment have any side effects?
  • Is surgery an option for me? Will I need to use eye drops after surgery?
  • Should I continue to drive?
  • Can I continue with my current activities?
  • Are there any lifestyle changes I should make?
  • Should I see an ophthalmologist?
  • Will my glaucoma get worse?