Astigmatism is a common visual distortion caused by an irregularly shaped cornea. The surface of the cornea is toric, oblong in shape like the side of a football, instead of perfectly spherical like a basketball. One surface or axis of the football is long with a shallow curve while the other surface is short with a steep curve. Light rays passing through an oblong cornea bend unequally, causing two focusing points. The result is blurred vision at most distances.

Astigmatism is typically present at birth. Over time the condition may slowly increase but generally it remains relatively stable over a lifetime. Forty-five percent of people who require vision correction have some degree of astigmatism. Symptoms include squinting, occasional headaches and eye strain. Astigmatism often accompanies myopia and hyperopia.

The irregular shape of an astigmatic eye produces two focusing points around the retina. The result is blur at all distances. A ‘toric’ lens corrects each toric irregularity so that light is properly focused on the retina producing clear vision at all distances.