Radial Keratotomy (RK) is a surgical procedure that can also correct nearsightedness by changing the shape of the cornea. Microscopic incisions of 90 percent depth, placed in a radial pattern like the spokes of a wagon wheel, reshape and flatten the central cornea, allowing light to focus more precisely on the retina. The length and number of incisions determine the effect of the surgery. Patients with less than three diopters of nearsightedness and stable prescriptions are the best candidates.Another alternative to LASIK and PRK eye surgery that has recently been approved by the FDA are implantable lenses known as refractive intraocular lens implants (RIOLs). Usually reserved for patients with extreme myopia, RIOLs are surgically placed either between the cornea and the iris or just behind the iris, to enable light to focus properly on the retina for clearer vision.