How does an IOL correct astigmatism?

An intraocular lens (IOL) is used during cataract surgery to replace the cloudy lens (cataract) that was removed. IOLs can correct nearsightedness, farsightedness and astigmatism. Astigmatism is where the front clear surface of the eye, known as the cornea, is not perfectly round but rather is shaped more like a football. Consequently, the steepness of the cornea results in light rays focusing at different points and results in a blurred image. IOLs that can correct astigmatism are known as “Toric IOLs.” They work by neutralizing the astigmatism and allowing the light rays to be focused on one clear point.