I tell my patients to wait one month. It is safe to wear contacts (cosmetic or prescription) after LASIK but you are correct, you should be properly fit for them by an optometrist first.
LASIK can be repeated, but most surgeons (myself included) only consider this in the early postoperative period. PRK (different than RK) is my preferred approach when performing an enhancement after LASIK because I feel that it is safer. You would need another evaluation to see if you are an appropriate candidate for an enhancement.
