Lasik is the most
commonly performed refractive
surgery procedure. Lasik, is actually short for
"laser-assisted in situ keratomileusis."
Lasik has
advantages over other procedures, including a relative lack of pain
afterward and the fact that good vision is usually achieved almost
immediately, or at least by the next day.
An instrument
called a microkeratome is used in LASIK eye surgery to create a
thin, circular flap in the cornea. Another way of making the flap is
with a laser.
The surgeon folds
the flap back out of the way, then removes some corneal tissue
underneath using an excimer laser. The excimer laser uses a cool
ultraviolet light beam to precisely remove very tiny bits of tissue
from the cornea to reshape it. When the cornea is reshaped in the
right way, it works better to focus light into the eye and onto the
retina, providing clearer vision than before. The flap is then laid
back in place, covering the area where the corneal tissue was
removed.
Both nearsighted
and farsighted people can benefit from the LASIK procedure. With
nearsighted people, the goal is to flatten the too-steep cornea.
With farsighted people, a steeper cornea is desired. Also, excimer
lasers can correct astigmatism, by smoothing an irregular cornea
into a more normal shape.
