Laser Eye Surgery (LASIK)
LASIK eye surgery can be an alternative to glasses or contact lenses done for the correction of certain common vision problems.
LASIK is a type of laser refractive surgery — the best known and most commonly performed. In general, a special type of cutting laser is used to precisely change the shape of your cornea — the dome-shaped transparent tissue at the front of your eye — to improve vision.
Normally, images are clearly focused on the retina in the back of your eye because the light rays are bent properly to contact the retinal surface. With nearsightedness (myopia), farsightedness (hyperopia) or astigmatism, the light is bent incorrectly and it ends up being focused elsewhere, resulting in blurred vision. Traditionally, the blurred vision is corrected by bending (refracting) light rays with glasses or contact lenses. But reshaping the cornea itself also will provide the necessary refraction.
Complications that result in a loss of vision are very rare. But certain side effects of LASIK eye surgery, particularly dry eyes and temporary visual disturbances, are fairly common. These usually clear up after a few weeks or months, and very few people consider them to be a long-term problem.
Risks of LASIK include:
Dry eyes. LASIK surgery causes a temporary decrease in tear production. For the first six months or so after your surgery, your eyes may feel unusually dry as they heal. Dry eyes can reduce the quality of your vision.
Your eye doctor might recommend that you use eyedrops during this time. If you experience severe dry eyes, you could opt for another procedure to get special plugs put in your tear ducts to prevent your tears from draining away from the surface of your eyes.
Glare, halos and double vision. After surgery you may have difficulty seeing at night. You might notice glare, halos around bright lights or double vision. This generally lasts a few days to a few weeks.
Even when a good visual result is measured under standard testing conditions, your vision in dim light (such as at dusk or in fog) may be reduced to a greater degree after the surgery than before the surgery.
- Undercorrections. If the laser removes too little tissue from your eye, you won't get the clearer vision results you were hoping for. Undercorrections are more common for people who are nearsighted. You may need another LASIK procedure within a year to remove more tissue.
- Overcorrections. It's also possible that the laser will remove too much tissue from your eye. Overcorrections may be more difficult to fix than undercorrections.
- Astigmatism. Astigmatism can be caused by uneven tissue removal. It may require additional surgery, glasses or contact lenses.
- Flap problems. Folding back or removing the flap from the front of your eye during surgery can cause complications, including infection and excess tears. The outermost corneal tissue layer (epithelium) may grow abnormally underneath the flap during the healing process.
- Vision loss or changes. Rarely, you may experience loss of vision due to surgical complications. Some people also may not see as sharply or clearly as previously.