cadet
lasik has only been in use for about 6-8 years. all of the different parts of the surgery, however, have been around for 20+ years.
for eg. the knife used to cut the flap, that technique has been used for 20+ years.
the laser used to make the correction, that technique has been used for at least 15 yrs.
in the past, there was 2 ways to do vision corrective surgery, the technique where you take a knife and cut radiating lines around the cornea and hope that it heals back successfully (not high probability and extremely painful).
the 2nd was even more painful, use the laser on w/o creating the flap. basically it burned the top layer of skin.
what lasik does is, first create a flap, you use a knife to cut a small flap of skin and you flip the flap out of the way.
then you take a laser and it atomized particles to shape the lense. the magic is when the put the flap back over. once that flap is back over you feel virtually no pain and you have about 80% of the vision that you will eventually get. it's pretty amazing procedure.
now, as to the horror stories. yes, there are many horror stories most of them occur because of the miscalculation on the part of the doctor. if all calculations are correct, the actual execution is almost guaranteed unless of course there is equipment failure.
as in anything human however, there is a chance of error.