Primary open-angle glaucoma
The aqueous humor, liquid produced by the eye, flows out of the eye through web-like channels. These channels ensure that excessive pressure isn’t built on the optic nerve. The primary open-angle glaucoma occurs when the drainage canals in the eye do not work as they should and the pressure within the eye and on the optic nerve increases.
This is the most common and most chronic type of glaucoma. Over 3 million Americans are diagnosed with primary open-angle glaucoma.
Primary angle-closure glaucoma
In this condition, the drainage canals in the eye are blocked by the iris and the pressure on the optic nerve is constantly high. The iris comes forward, away from its place, and closes-off the drainage canal.