During the past 8 years surgery of the cornea for refractive errors has risen to the rank of an independent, specialized discipline. It covers a range of techniques devised to correct or reduce all types of ametropia. Radial keratotomv is the operation most frequently performed to correct mild or moderate myopia from -1 to -6 diopters. Keratomileusis with or without freezing is a more complex procedure used to correct severe myopia of -8 to -16 diopters. Epikeratophakia for myopia or hypermetropia has a wider range of correction, ranging from 5 to 30 diopters. Each of these techniques has its own possibilities, limitations and risks. The main problem in this type of surgery if the predictability of its results. It is indicated essentially for cases where contact lenses have proved useless or are contra-indicated.
