EE WAS USING A BATTERY POWERED HAND DRILL TO INSTALL A SPAD IN THE MINE ROOF. WHILE DRILLING THE HOLE A PIECE OF ROCK (8"" X 2"" SQUARE) FELL FROM THE ROOF STRIKING HIM IN THE FACE RESULTING IN A SMALL PIECE OF ROCK GOING BEHIND HIS GLASSES. THE PIECE OF ROCK WAS CAPTURED UNDER HIS EYELID. THE ROCK WAS FLUSHED OUT BY A DOCTOR AND HIS EYES WERE COATED WITH IRRITAION MEDICATION.