The person must be 18 years or older with a stable power. A contact lens user must discontinue the use of contact lenses at least 2 weeks before the procedure. A detailed eye check-up is done to look for suitability for the procedure. Before the laser is done the eyes are checked with special machines to determine the exact power. The corneal mapping is done and corneal thickness is measured. In patients with high minus power a special retiona, which may need to be treated before the LASIK is performed. The LASIK laser is performed only after ruling out any contraindication and suitability of the procedure.