Undercorrection or overcorrection of your vision can occur for several reasons following this procedure. Usually, this results from healing that is not quite normal, at or around the surgical area or from an unusual response to the laser. Because everyone heals differently, it is difficult to predict who will develop an over-correction or under-correction. This can result in a decrease in your vision without glasses, but can be corrected with a pair of glasses. A repeat laser procedure can usually be performed in an attempt to improve the uncorrected vision and it is often successful. Your doctor may ask you to wait for a few months to let your vision to level off before doing a second treatment.