mine bulge and roll their eyes around in their sockets to rinse. How much misting is he getting?
Maybe a nice long warm shower, 15/20 min will help him clean out his eyes. It's a quick, easy, inexpensive thing to try first.
I mist on a timer 5min every 2 hours, plus a dripper and hand spray with really warm water everyday. plus weekly showers for all of them. I use about 30 gallons a week in misting!