Photorefractive surgery is performed using an excimer laser in an attempt to correct refractive errors such as short-sightedness (myopia), astigmatism, and more recently long-sightedness (hypermetropia). These refractive errors are usually corrected by spectacles or contact lenses. However, over the years a number of surgical techniques have been used to correct refractive errors, mainly myopia and these include 1) radial keratotomy (RK), 2) intracorneal rings, 3) automated lamellar keratectomy (ALK), 4) photorefractive keratectomy (PRK), photo refractive keratectomy with Epi-Flap(LASEK OR EPILASIK), photo-astigmatic refractive keratectomy (PARK) and hyperopic photorefractive keratectomy (H-PRK), 5) laser in situ keratomileusis (LASIK) 6) clear lens extraction, and 7) intraocular lenses.
This site provides information regarding surface excimer laser techniques to correct myopia, hypermetropia and astigmatism. e.g. photo refractive keratectomy with Epi-Flap(LASEK).
This is intended for persons with prescriptions up to -4.5D of short sightedness, -2.5D of astigmatism and +2.5D of hypermetropia.