One of the biggest factors in how happy you're likely to be with the results of your refractive surgery is your expectations about what the surgery will do for you.
A realistic expectation is that LASIK (or whatever refractive procedure your surgeon recommends) will reduce your dependency on eyeglasses and contact lenses and enable you to perform most everyday tasks without the need for corrective eyewear. For example, instead of needing glasses or contact lenses 100% of the time, you may need them only under certain situations, such as extended reading or driving at night.
It's true that many (if not most) refractive surgery patients can see perfectly well without eyeglasses or contact lenses after their procedure. However, it's likely you may still feel the need for eyeglasses for certain tasks after surgery. While some refractive surgery advertisements may lead you to believe the procedure will completely eliminate your need for glasses and contact lenses, this often is not the case.
Because refractive surgery changes the shape and structure of your cornea, your vision after your procedure may not be as "sharp" as it was with eyeglasses or contact lenses before surgery even if you can see the 20/20 line on the wall chart.
The lasers used in refractive surgery are very precise. But visual outcomes will differ from person to person for various reasons, such as individual healing characteristics, the degree of refactive error corrected and surgeon skill. Your expectations are too high and you are not a good candidate if you expect nothing less than perfect vision after refractive surgery.
See the Consumer Guide to LASIK & Laser Eye Surgery for more information.