Glaucoma is the most common neurologic eye disease in the world and the second leading cause of blindness in the United States. Glaucoma usually has no symptoms until it is in the advanced stages, and damage is irreversible. But, early detection can prevent a significant number of patients from experiencing any visual disability.
Glaucoma is a disease of the optic nerve, which connects the eye to the brain. The optic nerve is made up of many nerve fibers like an electric cable containing numerous wires. When pressure in the eye increases the nerve may be damaged causing blind spots to develop. If the entire nerve is destroyed, blindness results. In most cases their is no pain or redness and you can maintain excellent central vision until the final stages.

The most important risk factors are; elevated eye pressure, older age, African ancestry, a family history of glaucoma and significant eye injuries. Glaucoma can be associated with other types of eye surgery such as cataract and retinal.  Less strongly associated risk factors are diabetes, nearsightedness, hypertension and vasospastic diseases such as migraines and Raynaud's syndrome.
Since early detection and treatment are the keys to preventing loss of visual function, regular eye examinations by an ophthalmologist or optometrist are critical. Because glaucoma involves many factors, and some glaucoma damage occurs at normal pressures, simply getting an eye pressure screening is insufficient.