Which part of the body is affected by glaucoma?

Glaucoma is a group of eye diseases which result in damage to the optic nerve (or retina) and cause vision loss. Risk factors for glaucoma include increasing age, high pressure in the eye, a family history of glaucoma, and use of steroid medication.

If treated early, it is possible to slow or stop the progression of disease with medication, laser treatment, or surgery. The goal of these treatments is to decrease eye pressure.

About 70 million people have glaucoma globally. It occurs more commonly among older people, and closed-angle glaucoma is more common in women. Glaucoma has been called the "silent thief of sight", because the loss of vision usually occurs slowly over a long period of time. Worldwide, glaucoma is the second-leading cause of blindness after cataracts. Cataracts caused 51% of blindness in 2010, while glaucoma caused 8%.

The word "glaucoma" is from the Ancient Greek "glaukos", which means "shimmering." In English, the word was used as early as 1587 but did not become commonly used until after 1850, when the development of the ophthalmoscope allowed doctors to see the optic nerve damage.