Astigmatism is a vision condition that causes blurred vision due either to the irregular shape of the cornea, the clear front of the eye, or sometimes the curvature of the lens inside the eye. An irregular shaped cornea or lens prevents light from focusing properly on the retina, resulting in blurred vision at all distances.
Astigmatism frequently occurs with other vision conditions like nearsightedness (myopia) and farsightedness (hyperopia). Together these vision conditions are referred to as refractive errors because they affect how the eyes bend or "refract" light.
Astigmatism is a very common vision condition. Slight amounts of astigmatism usually don't affect vision and require treatment. However, larger amounts can cause distorted or blurred vision, eye discomfort and headaches. A comprehensive eye examination will include testing for astigmatism. Depending on the amount present, glasses or contact lenses may be prescribed to correct the astigmatism by altering the way light enters the eye.