OPERATOR WAS MOVING CONCRETE SAND STACKER AT WASH PLANT. OPERATOR WAS PULLING STACKER WITH A CHAIN. CHAIN GAVE WAY & HIT R. FRONT WINDOW, SENDING GOLASS INTO OPERATOR'S FACE & RIGHT EYE. OPERA TOR WAS TAKEN TO ER & FOUND GLASS IN RIGHT EYE. AFTER MEDICAL ATTENTION WAS GIVEN, OPERATOR WAS GIVEN A URINANALYSIS TEST & TESTED POSITIVE/ CONTRIBUTING TO ACCIDENT.