EE WAS WORKING IN THE NORTH SIDE OF THE FEED INGREDIENTS PLANT. THEY WERE LOWERING A DUCT FOR THE NEW SCRUBBER. THE WEATHER WAS DRY AND WINDY THAT DAY. A HOLE WAS CUT IN THE ROOF TO LOWER DUCT THROUGH. EE WAS WEARING SAFETY GLASSES AND HARD HAT WHEN DUST CAME DOWN FROM THE ROOF LEVEL. A PARTICLE OF DUST BECAME ENTRAPPED IN HIS LEFT EYE.