If your eye were to suffer injury early in the healing process, the flap could be dislodged and require immediate repositioning.

Because every eye responds a little differently to LASIK, it is possible that the desired correction may not be achieved. Most cases can be retreated with an enhancement procedure, but corrective lenses may also be necessary.

LASIK changes the shape of the cornea and there is a chance that contact lenses, if they are needed, may not fit easily or comfortably over the new surface.

It is possible that very small surface irregularities could result in a loss of best-corrected vision. There is a risk (less than 1 in 100) that two or more lines of vision on the eye chart could be lost.

Sometimes, especially with people who undergo high amounts of correction, the effect of surgery is partially lost over several months. In some, but not all cases, significant regression can be retreated.

Halos are an optical effect that may be noticed in dim light situations when the pupil dilates larger than the area of correction. As the pupil opens, a second ghost or faded image is produced by light passing through the untreated outer area of the cornea. Although this could interfere with night driving, it is rarely a significant problem.

Inconvenience between surgeries When both eyes are not treated the same day, the difference in correction can result in them not functioning well together.

An advantage of being nearsighted is that it may take until age 50 to be affected by presbyopia. However, if you are nearsighted and have successful LASIK treatment, you may need reading glasses in your early 40s, as is normal for most individuals.