Vision begins when light rays pass through the cornea (i.e., the clear window in the front of the eye) and lens. When all of the rays focus uniformly and strike the retina at the back of the eyeball, the result is called "perfect" or "20/20" vision.
Vision becomes impaired when the light rays focus at some point in front of or behind the retina. This occurs due to an imbalance between the shape of the cornea and the length of the eye. Everyone who reaches a certain age will at some point experience one or more of the following refractive errors.
Corrective Procedures
Each of the above vision problems can be corrected with refractive surgery. The advent of the excimer laser, which uses cool ultraviolet light to sculpt eye tissue, has revolutionized the refractive surgery field. Approved by the FDA in 1995, the laser is used to perform LASIK - the most popular elective medical procedure in the U.S. New refinements such as custom cornea mapping and a variation called EpiLASIK are making LASIK a great option for even more people. Non-laser innovations such as Phakic Intraocular Lenses (the ICLs) and Intraocular Lenses (IOLs) achieve excellent results for patients who are not good candidates for laser vision correction.
Which procedure is right for you depends on several factors, beginning with the source and degree of your refractive error, as well as your age. More information about vision disorders and corrective procedures.
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