it can impact your night time vision, but not that much for me. there are methods for lessening this impact, ask the doctor about it when they are determining if you can even have the procedure done. i didn't have that method(s) done, but my night vision is fine. if you want to get lasik and are worried about it, i believe if you ask for the method that pilots (including US Navy pilots) get done.
given that i had to wear pretty thick glasses or contacts, i am very very glad i had lasik done.
at this point i'd say the lasik is very proven. that said, this is all just my opinion, i'm not a doctor, and while something like 95% of people who get it done are very happy, there is that 5% that are not happy for some reason.
read about it yourself:
http://en.wikipedia.org/wiki/LASIK