LASIK surgery works by changing the shape of your cornea, that translucent covering over your pupil and iris (the colored ring in your eye). A successful procedure will result in a cornea that bends light rays, in a process called "refraction." This focuses them more accurately on your retina, the "back wall" or "screen" on which images are projected. LASIK corrects the shape of the cornea so it is properly focused at that point, instead of another point either in front of - or behind - your retina.

The development and continuing refinement of LASIK eye surgery has been bringing better, clearer vision to millions of people who once had to rely on glasses or contact lenses. With decades of experience and ongoing advances in the underlying technology, the safety and efficacy of the LASIK procedure is now well established. Of course, complications associated with laser eye surgery still exist so it is critically important for you to find out what the procedure involves, what can possibly go wrong and whether or not you are a good candidate for it.

LASIK may be a viable option for you if you are nearsighted, farsighted or have some forms of astigmatism, all of which are called "refractive errors." Nearsightedness means that the eyeball is somewhat longer than normal, or the cornea curves too much, which results in blurred distant vision as the light focuses in front of the retina. Farsightedness occurs when a "short" eyeball, or a cornea that is "too flat" focuses light behind the retina, blurring near vision (and sometimes distant vision too). Finally, astigmatism affects the focus of both near and distant vision if the cornea either curves and/or flattens unevenly.

Most eye doctors will probably recommend other types of vision correction before turning to LASIK eye surgery or a related procedure. Naturally, wearing glasses or contact lenses is the first alternative. As opposed to other eye diseases, these refractive errors are not necessarily progressive conditions, and may actually get better in middle age for some people. And there are some doctors who reject the need for LASIK eye surgery, claiming that your eyes are still healthy even with nearsightedness or farsightedness. The best approach for you is something that you will have to decide after a complete, careful evaluation of your eyes, your overall health and your expectations for the surgery.

Part of the process of determining if you're a candidate for LASIK eye surgery involves considering the particular risks it presents for some people. Your LASIK surgeon may advise you against this surgery if you have an immune system disease that reduces your capacity to heal after surgery. With an "autoimmune disease" like rheumatoid arthritis, or an "immunodeficiency disease" such as HIV, the risk of infection and other complications following laser eye surgery is greater.

Other conditions that may affect your suitability for the LASIK procedure are conditions that cause dry eyes, as they are likely to obstruct and delay the healing process. Doctors report that extremely uneven or abnormally shaped corneas may complicate matters, and if your vision is progressively worsening from other conditions you may be considered ineligible for laser eye surgery. In fact, even deep-set eyes and other facial-bone anomalies can make the procedure both riskier and more difficult.

Your LASIK surgeon will take into account all pertinent health factors. This article, like all those at DocShop.com, are intended to educate you and make you a better informed patient, not take the place of you doctor.