Glaucoma, a group of conditions that damage the optic nerve, is a leading cause of blindness for people 60 years of age and older. More than 60 million people worldwide, and about 3 million people in the U.S. are living with glaucoma. Yet only 50% of them may be aware that they have the disease—and many don’t know until it’s too late. Here are some glaucoma basics from the American Academy of Ophthalmology.*

What is glaucoma? How does it harm your vision?

The cornea and lens of your eye have no blood supply, so the eye produces a fluid called aqueous humor, which bathes the front of the eye and delivers nutrients. The aqueous humor also controls the amount of pressure inside the eye. 

When the fluid doesn’t drain properly, it builds up, causing an increase in pressure that, over time, damages the optic nerve. The optic nerve is actually a cluster of delicate nerve fibers that transmit information from your eyes to your brain.

Two of the most common types of glaucoma are:

• primary open-angle glaucoma, and
• angle-closure glaucoma.

Both types are asymptomatic in the early stages, which is why many people don’t realize they have glaucoma until significant damage has been done. Peripheral vision is usually lost first, eventually leading to complete blindness. 

Optic nerves do not regenerate, and there is currently no way to replace them or to restore vision once lost. This is why regular visits to the eye doctor are so important, especially for those who are at high risk. 

Who is at high risk for glaucoma? 

Glaucoma can occur in anyone, at any age, but the following factors increase your risk: 

• of black or Hispanic race; 
• close family members with glaucoma; 
• aged 60+ years (40+ if black); and  
• certain health conditions, such as diabetes and high blood pressure.

Other risk factors include:

• unusual appearance of the optic nerve (pale, enlarged);
• severe nearsightedness;
• eye injury or eye surgery; and
• corticosteroid use.

Is there a treatment for glaucoma?

If glaucoma is detected early, and acted upon quickly, a combination of medication and surgery to normalize pressure in the eye can halt the disease progression in 90% of cases. The earlier that you receive a diagnosis and treatment, the more likely it is that your sight can be preserved.

To learn more about glaucoma basics, check out the BrightFocus Foundation’s “Glaucoma: Essential Facts” PDF.

*Boyd, K. (2019, August 28). What Is Glaucoma?. American Academy of Ophthalmology.

Any sources from outside of Prevent Blindness do not imply an endorsement from Prevent Blindness. The contents of the material used are the responsibility of the authoring organization, Responsum Health.