Refractive surgery is used to correct common eye disorders such as nearsightedness, farsightedness, and astigmatism. Refractive surgery is designed to alter the shape of the cornea in order to improve the patient’s vision.
For people who are myopia, some refractive surgery techniques will minimize the curvature of a cornea that is too steep so that the eye's focusing power is lessened. Images that are focused in front of the retina, due to a longer eye or steep corneal curve, are pushed closer to or directly onto the retina following surgery.
Hyperopia people will have refractive surgery procedures that achieve a steeper cornea to increase the eye's focusing power. Images that are focused beyond the retina, due to a short eye or flat cornea, will be pulled closer to or directly onto the retina after surgery.
Astigmatism can be treated with refractive surgery techniques that selectively reshape part of an irregular cornea to make it smooth and symmetrical. The result is that images focus clearly on the retina rather than being distorted due to light scattering through an irregularly shaped cornea.