While working on the drive pier on #4 Kiln to adjust the up-hill thruster, metal particle flaked off the kiln. Strong wind conditions blew the particle in behind the safety glasses worn by Repairman. He noticed it that night & continued to work with his crew. The next day his rt eye became worse & he required med. attn to remove the f.b. & Rx drops to promote healing. RTW 9/16/08.