Astigmatism is when the cornea has an oval shape instead of round. This irregular curvature of the cornea causes light to focus on more than one point on the retina. Uncorrected astigmatism impairs both distance and near vision.
Astigmatism may occur in combination with myopia, hyperopia or presbyopia. It can be corrected with eyeglasses with a cylinder lens oriented at an angle that corresponds with the curvature of the cornea.
LASIK surgery is not recommended for people with presbyopia, because the procedure works on the cornea, not the lens, and usually corrects distance vision. If a person nearing the age of 40 were to have LASIK, it is likely that they would need reading glasses even sooner.