Lasik (laser in situ keratomileusis) is a combination of two procedures. First, either a special instrument called a keratome, or a laser is used to create a flap of corneal tissue on the surface of the eye. This is like splitting a layer cake in two halves. A computer controlled excimer laser is then used to reshape the surface of the bottom layer an amount determined to correct your vision. The laser works by removing layers of tissue from the center or periphery of the cornea, one by one. It?s like taking one sheet of paper off a tablet at a time. This tissue removal causes the cornea to become flatter or steeper (depending on whether you are near or farsighted), causing light rays to focus more directly on the retina to create a clearer picture. The corneal flap or upper layer is then placed back in its original position, covering the lasered area. The eye holds the flap in place naturally and sutures are rarely needed. The resulting flattening or steepening of the cornea causes light rays to focus more directly on the retina, making images clearer, without the use of glasses or contact lenses.
The standard lasik procedure, uses "averages" for the laser treatment algorithm, and is suitable for most people. The new "Wavefront" Custom Lasik, treats each individual eye separately and does not use averages, having the potential for even more accurate/better visions.
(see visxS4 tab, far left page for further detail on custom laser treatment).

The advantages of the Lasik procedure are (compared to PRK):

1.) Less post-operative discomfort
2.) Faster visual recovery?usually 1-2 days.
3.) The ability to perform the procedure on both eyes at the same time
4.) The ability to correct up to 12 units of Nearsightedness, 4 units of farsightedness and 4 units of astigmatism

The disadvantages of this procedure are (compared to PRK):

1.) It is a technically more difficult procedure for the surgeon

2.) There are more potential risks than with PRK or LASEK.

This procedure is presently the most commonly performed refractive surgery procedure in the world for correction of nearsightedness, farsightedness and astigmatism.


1. Delayed epithelial or poor epithelial healing which can lead to scarring, vision loss or further

2. Under or over correction which may lead to further surgery or may not be correctable

3. Night halo, glare and ghosting can occur with any of these procedures and has an
increased incidence when astigmatism is corrected and in people with larger than
normal pupils. These effects usually fade with time, but may be permanent.

4. Light sensitivity can occur for a short time after these surgeries. This usually fades with time but can be permanent.

5. Corneal haze or scarring can occur with these Procedures. This usually diminishes with time and
does not affect the vision but in some cases may be permanent and/or effect vision.

6. Eye co-ordination: when both eyes need correction, there is a problem with eye co- ordination aftersurgery has been done on one eye. Wearing glasses, a patch or contact lens may be necessary until both eyes can be corrected.

7. Contact lens tolerance may be diminished after these procedures

8. Bilateral surgery (both eyes) entails all the same risks as single eye surgery, however, if complications do occur, they may affect both eyes leading to loss of vision in or loss of, both eyes.

9. Infection can occur in these procedures and can be blinding or lead to loss of an eye

10. Dry eye syndrome may result from these surgeries or become worse in previously affected individuals

11. Corneal thinning and progressive ectasia may occur and lead to the need for corneal transplantsurgery

12. Unknown or presently unanticipated complications can occur with these procedures leading to loss of vision or loss of an eye(eyes) at present or in the future.

13. To prevent injury after surgery, all patients MUST wear certified sports goggles or safety glasses duringsports or work where potential for eye injury exists.