The Vegas Strip just lost some of its luster. After a number of close calls, including an October 30 incident in which a co-pilot had to take the controls from a temporarily blinded pilot, the Food and Drug Administration has ordered Las Vegas casinos to shut down their nightly laser light shows over the city. The FDA, which regulates lasers because of their use as medical devices, made the order in response to complaints from pilots who have been momentarily blinded as light beams flash through their cockpits. The problem has accelerated in the past two years as a number of casinos began showing nightly laser light shows. FDA compliance official Lillian J. Gill said the ban affects only Las Vegas, but could be extended to other areas where outdoor laser light shows impair airplane pilots.