You are suggested to stop wearing contact lenses for some days before LASIK Eye Surgery. That is because the contact lenses can change the shape and thickness of the cornea temporarily to some degree. If you wearing contact lenses before take the surgery, it will affect your pre-operative exam, that increase the rate that a poor visual may outcome from LASIK. So, for the sake of your eyes, you shall stop wearing contact lenses before lasik surgery.
Absolutely, you should not wear contacts at least for one week before you take the LASIK. For one reason, you know, before you take the surgery, the doctor needs to examine your eyes to see whether it is suitable for you to have such an operation. Wearing contacts may change the thickness and shape of your cornea, so the doctor cannot get the accurate statistic about your eyes, thus it is bad for his analysis on your surgery. For another reason, the contacts, although often cleaned, there still are many bacteria on the surface of the lens. If you had the LASIK on the very day when you wear contacts, how can you guarantee that there will exist no bacteria in your eyes and you will get infection during and after the surgery, which is not good for your healing process. So you are recommended not to wear contacts at least for one week before the surgery.