Has he shed latley?
Sometimes they get little pieces of shed in their eyes.
Get a large spray bottle, fill it with warm (not hot) water, adjust the sprayer
nozzle to spray a coarse spray insted of a mist.
Spray him directly, from above, like rain.
Use the whole bottle, make sure he gets a good long bath.
They use the water to help clean their eyes.
Do this twice a day.
If no relief, you can buy eyedrops for reptiles, but I have never needed to use
it because the warm showers have always worked for me.
You can spray him while in his cage, this way, he will be less stressed then if
you took him out.