Since being brought to market in the early 1990s, tens of millions of people around the world have taken advantage of Lasik eye surgery and put away the eye glasses and contacts forever. The procedure is relatively cost-effective and simple, yielding positive results for the majority of Lasik patients. But how many of those patients know the science behind Lasik?
Lasik is an acronym for the medical term "laser in situ kertomileusis". The term describes, in essence, what the procedure does; it uses a low level laser to reshape the cornea, the eye's transparent covering. In patients with near and far-sightedness the cornea is often misshapen, causing blurry vision at certain distances. By reshaping the cornea most patients can expect between 20/20 and 20/40 vision after the procedure. Lasik also seems to be effective astigmatism, an abnormal curvature of the cornea which, under normal conditions, is the shape of a half-moon.
With near-sighted patients the cornea has too much point at the crown of the curve. The laser is used to remove excess tissue and thus, remove the point. Far-sighted patients have the opposite problem; a cornea which is too flat. In this case the laser is used to remove tissue on the perimeter, forming the proper curve. With astigmatism the corneal defect can be manifested in several ways, but the process of removing tissue to restore corneal shape is the same.
As Lasik science has advanced over the years, great strides have been made in using lasers to treat other vision problems as well. Cataract sufferers, for example, begin to lose their vision as calcium deposits from behind the cornea. This condition often rendered its victims blind in past years, but with the same low-level laser an ophthalmologist can now quickly and safely open the cornea and remove the cataract completely. The cornea's ability to self-heal very rapidly after the procedure makes the use of Lasik even more attractive for cataract patients.
Though Lasik eye surgery can be an effective treatment for a number of vision problems, it does not address the underlying issue which caused the distress to begin with. Normal aging, as well as other health-related issues can once again cause the cornea to lose its proper shape, thus mitigating the benefits of the surgery. However, in most cases the return of poor vision takes quite a long time, making the benefits of the surgery well worth the risk.By Yang Yang