The U.S. Air Force approves the use of PRK and LASIK. Since 2000 the USAF has conducted PRK for aviators at the Wilford Hall Medical Center. More airmen were allowed over the years and in 2004 the USAF approved LASIK for aviators, with limits on the type of aircraft they could fly. Then in 2007 those limits were lifted. Most recently in 2011 the USAF expanded the program, making it easier for more airmen to qualify for the surgery. Current airmen (Active Duty and Air Reserve Components who are eligible) are authorized surgery at any DOD Refractive Surgery Center. Those airmen not eligible, are still able to get the surgery done at their own expense by a civilian surgeon, but must first be approved (approval is based on the same USAF-RS program). Others that do not fall into those categories (i.e. applicants who are seeking a pilot slot) can still elect to have the surgery done, but must follow the criteria in accordance with the USAF Waiver Guide. Those applicants will be evaluated at the ACS during their Medical Flight Screening appointment to determine if they meet waiver criteria.