The Excimer laser is used to change the curvature of the cornea to eliminate the refractive error. The goal is to reduce your dependence on glasses and/or contact lenses.
The LASIK Procedure for Nearsightedness
Also called myopia, nearsightedness exists when the eye has too much focusing power for its length. The eye may be too rounded, or too long - either way, light is focused short of the intended target, the retina. In practice, most people have nearsightedness from eyes longer than average, with a fairly normal curvature of the eye.
The most common method we use today is to flatten the front (corneal) surface slightly, reducing the basic power of the eye. Alternatively, we could remove the internal lens of the eye, and perhaps replace it with another lens of a lesser power. This method also works, but is usually reserved for eyes with extreme amounts of nearsightedness because it involves more invasive surgery than other methods.
LASIK is a procedure that takes advantage of the laser’s accuracy, yet LASIK spares the corneal surface, overcoming the deficiency of PRK. LASIK is basically the same as PRK, except that it is performed beneath the surface of the eye. The surface is moved out of the way before the laser is used, by creating a thin flap, which is replaced when the procedure is done. The flap protects the surgical area, and heals back into place very quickly - in a matter of a few hours.
Visual recovery is very rapid with LASIK, and discomfort is minimal. How rapid? Most people can return to work the first day after surgery!
Long term, LASIK results are more stable than PRK results. This is because the surface is left in its normal condition, so it does not undergo the prolonged healing of PRK. The healing beneath the surface is very rapid, and stable.
The LASIK Procedure for Farsightedness
Also called hyperopia, farsightedness is the opposite of nearsightedness. In farsightedness, the eye has too little focusing power for its length. Farsighted eyes tend to be small in size, and less curved (flatter) than normal.
At Emara Laser Eye Centers, we primarily use LASIK for the corrections of farsightedness, similar to the LASIK described for nearsightedness. LASIK results are more stable than other procedures and can correct higher prescriptions.
In this procedure, a thin flap of surface tissue is moved to the side, like the cover on a book. The laser is then used to reshape and properly round the cornea, increasing its power. The surface layer is repositioned at the end of the procedure.
In some case (extreme farsightedness; age factor) a lens extraction can be performed. This is similar to a cataract procedure. In either case, the objective is to give the eye more focusing power, achieving clear images.
The LASIK Procedure for Astigmatism
Astigmatism is a condition where the corneal surface of the eye is off-round, or warped. Astigmatism often occurs with nearsightedness or farsightedness, although it can exist on its own.
Astigmatism is correctable with the LASIK procedure utilizing specialized software in the excimer laser. At Lasik Centers of America, we have been successfully correcting astigmatism with the NIDEK laser since 1999.