EMPLOYEE WAS WELDING ON A BEAM WITH A WELDING HOOD AND HAD SAFETY GLASSES UNDER THE HOOD THAT WERE TINTED. WHEN HE RAISED HIS HOOD TO CHIP THE SLAG, HE HAD HIS SAFETY GLASSES SLID DOWN ON HIS NOSE. HE FELT SOMETHING IN HIS EYE, BUT NOTHING COULD BE FOUND BY FIRST AID PROVIDER ON SITE. WAS NOT AWARE PRESCRIPTION WAS GIVEN UNTIL 12/3/02.