My aim is to help you achieve the best possible vision in the safest way.  Laser vision correction is not intended to increase your vision potential.  You should not expect to read 20/20 following the procedure if you were unable to read 20/20 with glasses before the procedure.  The combination of magnitude of your prescription, the size of your pupil in dim light and the thickness of your cornea may make it impossible to fully correct your prescription in a safe manner and, in these instances, a weaker prescription would still be necessary following the procedure (planned undercorrection).

Regression or loss of effect (the return of some myopia, hyperopia and/or astigmatism) is related to individual healing responses and may lead to a difference in the vision in each eye or less than "perfect" vision.  Statistically regression is more likely to occur in higher prescriptions but it can occur in anyone.  Retreatments (enhancements or touch-ups) can be performed when healing is complete and the vision has stabilized (3 months) provided that the amount of the regression is of sufficient magnitude to warrant retreatment and that it can be done safely.  For very small amounts of residual prescription the risks of performing a retreatment may outweigh the potential benefits and a retreatment would be ill advised.

Laser vision correction will not treat ocular disease nor will it prevent diseases which you were prone to develop.