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