Eye Anatomy




Healthy Drainage





The Eye With Glaucoma

In most types of glaucoma, the eye’s drainage system becomes clogged so the intraocular fluid cannot drain. As the fluid builds up, it causes pressure to build within the eye. High pressure damages the sensitive optic nerve and results in vision loss.

The Optic Disc

You have millions of nerve fibers that run from your retina to the optic nerve. These fibers meet at the optic disc. As fluid pressure within your eye increases, it damages these sensitive nerve fibers and they begin to die. As they die, the disc begins to hollow and develops a cupped or curved shape. If the pressure remains too high for too long, the extra pressure can damage the optic nerve and result in vision loss.

Is There Another Cause?

It was once thought that high intraocular pressure (IOP) was the main cause of this optic nerve damage. Although IOP is clearly a risk factor, we now know that other factors must be involved because people with “normal” IOP can experience vision loss from glaucoma.

The Fluid Inside

Aqueous humor is the clear, watery fluid that is continually produced inside the eye. It is different from your tears. Tears are produced by glands outside of the eye and moisten the outer surface of the eyeball.


You can also find the information in this article in our free booklet Understanding and Living with Glaucoma. Order your free copy»

Last reviewed on September 05, 2013

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