LASIK (Laser In-Situ Keratomileusis) for Nearsightedness

Surgery Overview

LASIK (laser in-situ keratomileusis) is a surgery that flattens the cornea. It is the most common laser surgery for correcting nearsightedness (myopia) and astigmatism. LASIK makes a small flap in the cornea and removes some of the tissue exposed by the flap. The laser removes tissue from the cornea very accurately without damaging nearby tissues.

What To Expect After Surgery

LASIK is an outpatient procedure. It is done under local anesthesia in a surgeon's office or a same-day surgery center. The operation on one eye takes about 10 to 15 minutes. The entire process usually takes less than 2 hours, including preparation time, care right after the surgery, and paperwork.

After surgery, you may wear a patch or contact lens on the eye and get a prescription for pain medicine. Someone must drive you home and then back to the surgeon's office the next day. During this second visit, the surgeon will examine your eye and prescribe eyedrops to prevent infection and reduce inflammation. More follow-up visits are required, usually the next week and then throughout the first year after surgery.

  • You will feel irritation and scratchiness in the eye on the day of surgery. Your eyes may water a lot.
  • Recovery is usually quick, with only mild discomfort. You may return to your normal activities within a few days.
  • Dry-eye symptoms are common but usually temporary.
  • You may need to wear an eye shield for a few days after surgery.
  • Your vision may be hazy or blurry for a few days or a week after surgery. Do not drive until your vision has cleared.
  • For 2 weeks after surgery, avoid vigorous sports, eye makeup, and activities that may get water in the eye. The surgeon may recommend that you shower before the surgery and then avoid showering for a day or two afterward to keep from getting water in the eye.

LASIK usually requires very little recovery time. Most people who have the surgery see quite well the next day. There is little or no pain after LASIK.

Why It Is Done

LASIK is an elective, cosmetic procedure that is done to correct nearsightedness in otherwise healthy eyes.

LASIK surgery may be used to correct mild to moderate nearsightedness. It is also thought to be the best procedure for correcting high nearsightedness (greater than 7 diopters), although the results of surgery become harder to predict with higher amounts of nearsightedness.

How Well It Works

Over the short term, LASIK has been shown to be very effective in reducing mild to moderate nearsightedness (myopia). Almost everyone notices improvements in their vision. But not everyone gets perfect 20/20 vision.

For people with myopia of less than 6 diopters, studies showed that after surgery, about:footnote 1

  • 67 to 72 out of 100 had 20/20 vision or better.
  • 95 to 96 out of 100 had 20/40 vision or better.

For people with myopia between 6 and 12 diopters, studies showed that after surgery, about:footnote 1

  • 48 to 64 out of 100 had 20/20 vision or better.
  • 89 to 94 out of 100 had 20/40 vision or better.

Doctors continue to improve the technique and to study the long-term results.


The risk of complications from LASIK surgery is low and decreases with a more experienced surgeon. Look for a corneal specialist or surgeon who does the surgery often.

Complications and side effects from LASIK may include:

  • Clouded vision (clouding of the cornea as a result of inflammation during healing). The inflammation usually goes away on its own. But your doctor may give you medicine or do a procedure to relieve the inflammation.
  • Night vision problems, such as halos (often described as a shimmering circle around light sources such as headlights or street lamps).
  • Glare, or increased sensitivity to bright light.
  • Double vision (diplopia), usually in one eye.
  • New astigmatism caused by wrinkling in the corneal flap or other flap complications.
  • Loss of best corrected vision, which is the best possible vision you can achieve using glasses or contact lenses.
  • Overcorrection or undercorrection.

Serious vision-threatening complications are rare but may include:

  • Infection of the cornea (keratitis).
  • Elevated pressure inside the eye (intraocular pressure) leading to glaucoma.

LASIK has been approved by the U.S. Food and Drug Administration (FDA) since 1995. But the procedure may have long-term side effects or complications that experts do not yet know about.

What To Think About

If you are thinking about having surgery to improve nearsightedness, you may have a number of options. Talk with your doctor about all the options, including their benefits and risks.

LASIK is being done more frequently than PRK, largely because of the good results and the quicker visual recovery that LASIK offers. There is no agreement about whether LASIK is superior to PRK or vice versa for people with mild to moderate nearsightedness.

Talk with your doctor about the risks and benefits of correcting both eyes on the same day compared with doing one eye at a time on separate days.

Ask your eye doctor for your original eye measurements—the ones that he or she took before LASIK was done. It is important to keep them with your other medical records in case you ever need cataract surgery. They help the doctor calculate future lens implants after cataract surgery. To learn more about record-keeping, see the topic Organizing Your Medical Records.

LASIK is a cosmetic procedure. The cost of refractive surgery varies in different locations, but it can be a big expense. Most insurance companies do not cover the cost of refractive surgery.



  1. Sakimoto T, et al. (2006). Laser eye surgery for refractive errors. Lancet, 367(9520): 1432–1447.


Current as of: August 31, 2020

Author: Healthwise Staff
Medical Review:
Kathleen Romito MD - Family Medicine
Adam Husney MD - Family Medicine
Christopher J. Rudnisky MD, MPH, FRCSC - Ophthalmology

LASIK (Laser In-Situ Keratomileusis) for Nearsightedness