Astigmatism is a deficiency of the eye and can occur between the times of birth and adulthood. Everyone has a cornea which permits light to come into the eye. When astigmatism occurs the cornea is shaped irregularly preventing the maximum amount of light from entering the eye. A normal cornea has the shape of a basketball but a cornea with astigmatism is shaped like a football. It can also be caused because of an irregular shaped lens. The lens of the eye is behind the cornea and its function is to focus the rays of light into a part the eye called the retina. The retina is the part of the eye that sends the rays into focus and then transmits the info to the brain and an image is what appears. If astigmatism is caused by an irregularly shaped cornea it is called corneal astigmatism. If astigmatism is caused by an irregularly shaped lens it is called lenticular astigmatism. Both situations can be treated and possibly corrected with glasses, contact lenses or refractive surgery.