There are two basic types of astigmatism; myopia and hyperopia. These two types affect up to one third of the population and can be treated in a variety of ways from corrective lenses to surgery.

Myopia, or nearsightedness occurs when the eyeball is slightly longer than usual from front to back or the shape of the cornea is too steep. This causes the light entering the eye to come to a focus in front of the retina which results in a blurred distance vision.

Hyperopia, or farsightedness is the opposite of myopia. It occurs when the eyeball is slightly shorter than normal, or the shape of the cornea is too flat. This cause the light entering the eye to come to a focus behind the retina, which results in blurred near vision. Distance vision may also be blurred depending on the severity of hyperopia.

Glaucoma is a disease that affects the optic nerve. The disease causes optic nerve damage, which leads to partial or total vision loss. These two types of glaucoma both stem from a problem in the angle between the cornea and iris of the eye. They are called Narrow Angle and Closed Angle Glaucoma.

Narrow Angle glaucoma can develop either quickly or slowly and usually occurs in people with farsightedness. It occurs when the angle narrows causing the aqueous fluid to build up. This narrowing is caused by a bowing of the iris. Narrow Angle glaucoma can only be detected through routine eye examinations. It can cause vision loss and can also lead to an emergency condition called closed angle glaucoma.

Closed angle glaucoma, also called angle closure glaucoma, develops quickly and is a medical emergency. It occurs when the iris bows forward so much that the angle is completely closed. That means that no aqueous fluid can escape, which causes the pressure to build up rapidly. There...