WWII VARIABLE-DENSITY GOGGLES Stock no. 74-G-79-40.  INCLUDES TIN, EXTRA LENSES AND INSTRUCTIONS.  

These were used by U.S. aerial gunners and anti-aircraft gunners.  They are equipped with a turning dial on the front allowing the pilot to alter the tint of the lens thus enabling them to see tracer rounds and not be easily blinded. They failed to gain popularity in the military, however, and were phased out soon after the Second World War. They were more accepted by AAA gunners than aircrew, as it was one more piece of equipment that would have to carry onto their airplanes