Glaucoma is an eye disease in which internal pressure of your eye rises to a point that the Optic nerve is damaged. This pressure rise is usually due to an overproduction of fluid in the eye or inadequate drainage of the fluid. The exact cause for glaucoma is not known. For some reason the passages that normally allow to drain become clogged or blocked. This buildup of fluid inside the eye causes the internal pressure to rise and tissue damage occurs.

Glaucoma is detected by performing and evaluating a series of three basic tests. The visual Field exam in fig 1 measure the sensitivity of the Optic Nerve and yields a report as seen here.

The pressure inside the eye is measured by Tonometry. This quick and painless test is shown here.