Laser eye surgery includes a variety of techniques that employ a computer-guided laser to reshape the cornea of the eye to achieve optimal focusing length. Sound confusing? It really isn't.

When light enters the eye, it passes through the curved, clear cornea at the very front of the eye. The curvature of the cornea determines the distance at which light is focused within the eye; too much or too little curvature and the result is near- or far-sightedness. Glasses have always been the most practical way to correct for such deviations. Until now.

Now, there is technology that can reshape the cornea through laser eye surgery. The most common type of laser eye surgery is known as LASIK (laser assisted keratomilieusis). Another type of laser eye surgery is know as PRK (photorefractive keratectomy). These two types of laser eye surgery both use lasers to selectively vaporize tissue within the cornea, thereby reshaping it to the optimal shape. The difference between these two types of laser eye surgery lies in how the inside of the cornea (the "stroma") is exposed.

In PRK, the top, outer layer of the cornea is scraped away. In LASIK, a very fine knife is used to cut a flap off the top of the cornea and fold it back; after the laser performs the necessary reshaping of the stroma, the flap is folded back and naturally heals.

Both types of laser eye surgery can be used to correct the various "refractive" (or light-bending) errors caused by a poorly shaped cornea. These refractive errors include myopia (near-sightedness), hyperopia (far-sightedness) and astigmatism (blurriness caused by irregularities in the shape of the cornea). Your eye doctor can help you select the laser eye technique that's right for you.

So, are you a candidate for laser eye surgery? Laser eye surgery may be appropriate for you if you: are 21-60 years of age (or older if you are free of cataracts), have a refractive error without any other type eye disease (e.g. diabetes, rheumatoid), and have had stable vision for the past three years. If you meet all these criteria, laser eye surgery might be right for you.