ASTIGMATISM

The basic process of sight begins when light rays enter the eye through the cornea, the front surface of the eye. The cornea begins bending the light rays toward the back of the eye. The light then passes through the lens of the eye, which directs the rays toward an exact spot on the retina in the back of the eye. When that light reaches that perfect spot on the retina in a normal eye, the image seen is clear and in focus.

Astigmatism occurs when the cornea, the front surface of the eye, is irregular in shape, not spherical as it should be. The astigmatic cornea is "football" shaped. Because of the distorted cornea, light rays entering the eye are not directed to that exact spot on the retina that is vital for clear vision. This misdirection results in distorted vision, often like looking into a wavy mirror. Astigmatism can be corrected with glasses or contact lenses.