EMPLOYEE WAS GRADING MINE ROAD IWTH GRADER DOORS OPEN TO COOL CAB AS AIR CONDITIONING WAS NOT WORKING. EMPLOYEE WAS WEARING SAFTY GLASSES. DUST FROMT HE ROAD BLEW ITNO CAB OF GRADER AND PERL ITE BLEW INTO EMPLOYEE'S EYES. PERLITE WOULD NOT WASH OUT OR COME OUT OVERNIGHT. EMPLOYEE REPORTED INCIDENT FOLLOWING DAY (06-06-00) AT WHICH TIME HE WENT TO THE DR.