Reviewed by Karanjit S. Kooner, M.D.

Updated by Sefy Paulose, M.D., March, 2022

Glaucoma is a group of eye diseases that can lead to blindness by damaging the optic nerve. In a healthy eye, fluid called the aqueous humor is continuously produced and then drained appropriately to maintain a healthy eye pressure. However, in some cases, the production of aqueous is too high or the drainage system itself is blocked causing pressure to build within the eye. Overtime, this increased pressure can damage the optic nerve.

The optic nerve transmits information from the eye to the brain. For example, you can think of the eye as a camera which obtains information from the outside world and the brain as a computer which processes that information. In this example, the optic nerve is like a cable which connects the eye (or the camera) to the brain (or the computer), allowing information to be passed for processing.

With periods of elevated pressure in the eye, damage first occurs in the outskirts of the optic nerve which then results in peripheral (or side) vision loss. The effect can be like looking through a tube or into a narrow tunnel, making it difficult to walk without bumping into objects that are off to the side, near the head or at the foot level. As the disease progresses and the optic nerve damage continues, the field of vision constricts until complete vision is lost. This is why glaucoma is often called the “sneak thief of sight” as the symptoms or early warning signs of glaucoma are very subtle.

Glaucoma can happen in 1 eye or both eyes. 

This is a representation of peripheral vision loss, or a constricted visual field:

A living room viewed through a constricted visual field


A living room viewed through a constricted visual field.
Source: Making Life More Livable. Used with permission.

Glaucoma Can Be Treated, Not Cured

Glaucoma can be treated, but it is not curable. The damage that has happened to the optic nerve from glaucoma is irreversible. However, lowering the pressure in the eye can help prevent further damage to the optic nerve and further peripheral vision loss.

Early detection through a comprehensive eye exam, appropriate and ongoing treatment, and the availability of specialized low vision and vision rehabilitation services can help people with glaucoma live productive and satisfying lives.

More Information

For more detailed and patient-centered information about glaucoma detection, treatment, and everyday management, see VisionAware’s Patient’s Guide to Living with Glaucoma and GuĂ­a del Paciente: Vivir con Glaucoma.

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