According to WebMD, contact lenses for astigmatism are specially shaped lenses intended to correct the refractive errors caused by astigmatism. Soft toric lenses can correct mild astigmatism, and special rigid lenses can correct more severe astigmatism.
WebMD explains that astigmatism is caused by eyes that are not completely round. The irregular shape of the eye causes the light to bend unevenly. People with astigmatism often find that parts of objects are blurry and wavy while other parts are in focus. WebMD says that contact lenses that correct astigmatism are unevenly shaped in order to correct for the uneven shape of the eyeball, causing the entire visual field to come into focus.