RisksBy Mayo Clinic staff
As with any surgery, LASIK eye surgery carries risks, including:
- 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 refractive surgery (enhancement surgery) 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.
- 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. Sometimes these problems can be treated with eyedrops that contain a type of corticosteroid, but a second surgery may be required. 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.
- Dry eyes. LASIK causes a temporary decrease in tear production. For the first six months or so after your surgery, as your eyes heal they might feel unusually dry. 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 eye, 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.
- Flap problems. Folding back or removing the flap from the front of your eye during surgery can cause complications, including infection, excess tears and swelling. The outermost corneal tissue layer (epithelium) may grow abnormally underneath the flap during the healing process.
Certain health conditions can increase the risks associated with LASIK surgery or make the outcome less predictable. These include autoimmune disorders, such as rheumatoid arthritis, immunodeficiency conditions caused by immunosuppressive medications or HIV, persistent dry eyes, pregnancy, unstable vision, and a condition of the cornea called keratoconus. For some people who are farsighted, an initial satisfactory result may decrease with age. If you have fairly good overall vision, severe nearsightedness, very large pupils, or you participate in contact sports that may be associated with blows to the face, LASIK may not be advisable.
If you're considering LASIK eye surgery, talk to your doctor about your questions and concerns. He or she can explain how the surgery might benefit you and help put the risks in perspective.
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