Astigmatism is an abnormal curvature of the window of the eye, the cornea, resulting in two or more focal points instead of one. In astigmatism, the cornea has a steep curvature and a flat curvature, much like the surface of a football. Light passing through the multiple curvatures causes blurring of the image. Most people have some degree of astigmatism.
Correction of astigmatism is required to clear the vision whether the correction is being done by glasses or contact lenses, laser vision correction, or cataract surgery. Other than glasses and contact lenses, there are two methods of astigmatism correction - astigmatic keratotomy or toric intraocular lenses.
Surgically, one of the ways the cornea can be adjusted is by making precise curved incisions on the steep curvature of the cornea. When correctly performed, the cornea assumes a perfectly round shape, allowing focus of all light passing through it into one spot.
During cataract surgery, an toric artificial lens used to replace the defective human lens removed during the procedure can be selected to correct astigmatism. A toric lens removes the need to make the incisions described above. Certain limitations exist if there is a high degree of astigmatism, and sometimes the two procedures must be combined.
Laser vision correction incorporates resolution of nearsightedness, farsightedness and astigmatism. The laser reshapes the cornea removing most or all of optical imperfections.
Ask your doctor about correcting astigmatism during your evaluation. Doing so will decrease your dependence on glasses for distance vision after cataract surgery or laser vision correction.