Glaucoma usually affects side (peripheral) vision first. If glaucoma is not treated, vision loss will continue, resulting in total blindness over time. If glaucoma is identified early and treated appropriately, good eyesight can usually be maintained.

Open-angle glaucoma, the most common type of glaucoma in the United States, usually affects both eyes at the same time. However, one eye may be affected more than the other. In open-angle glaucoma, vision changes so slowly that much of your eyesight may be affected before you notice the condition.

• Increased pressure and other factors gradually damage the optic nerve.
• Side (peripheral) vision is affected first. Blind spots from each side of the field of vision gradually meet, increasing the area of blindness. Central vision, used for reading and seeing details, is affected last.
• If untreated, open-angle glaucoma affects central vision, leading to permanent total blindness.

Closed-angle glaucoma is less common and usually affects only one eye at a time. About half of people who have closed-angle glaucoma develop the condition in the other eye within 5 years.³

Acute closed-angle glaucoma develops suddenly and is an emergency medical situation.

• The blockage of fluid drainage from the eye causes a sudden rise of pressure in the eye.
• If not treated promptly, the pressure in the eye leads to rapid, permanent damage to the optic nerve.
• Severe and permanent vision loss can develop within hours or days after symptoms develop.

You may have short episodes of closed-angle glaucoma. Without treatment, these recurrent episodes can develop into an emergency situation (acute closed-angle glaucoma) or become a long-term problem (chronic closed-angle glaucoma). If chronic closed-angle glaucoma is not treated, you will gradually lose your sight and you may become completely blind.

Glaucoma that is present at birth (congenital glaucoma) or that develops within the first few years of life (infantile glaucoma) is rare. However, it can be very serious. If congenital glaucoma is left untreated, permanent blindness can develop rapidly.

Treatment for any type of glaucoma may delay or prevent further vision loss, but it cannot reverse vision loss that has already occurred. In a few rare cases of congenital glaucoma, some reversal of the damage to the optic nerve has been seen.

If you have glaucoma, normal use of your eyes (such as for reading or watching television) will not speed up vision loss or make the condition worse.

How significantly your life will be affected depends on the severity of vision loss and your lifestyle. For information on how to live with low vision, see the Home Treatment section of this topic.