Radial keratotomy (RK), a surgery that is designed to reshape the cornea so that light focuses correctly on the retina, is supposed to make eyeglasses or contact lenses that correct for nearsightedness unnecessary
Yet a study of patients who have undergone RK shows that some of them still need to wear glasses or contact lenses
RK patients who originally suffered from only mild nearsightedness may, if the cornea does not heal evenly, develop an astigmatism that requires corrective lenses.