Who is a really good candidate for LASIK, and can it permanently cure severe myopia?

As your questions suggest, LASIK is overwhelmingly a treatment for myopia (nearsightedness) with any associated astigmatism. It is NOT usually a good treatment for farsightedness, particularly the most common, age-related type: Presbyopia. The BEST candidates for LASIK are under 45, have normal tear function, no signs of any eye pathology, and are not over about -6 or so diopters of myopia.

LASIK will NOT reverse or prevent the typical aging problems of vision such as presbyopia in middle age and later cataracts. While you will likely never go back to being as myopic as you were before having LASIK, there may be some changes in your distance vision many years later. These are NOT due to the LASIK "wearing off" but rather the normal age-related changes in the natural lens of the eye.

_Written by J. Trevor Woodhams, M.D. - Chief of Surgery, Woodhams Eye Clinic