Spray him with warm water early in the morning. Do it soon after he wakes up, but not immediately when he wakes up. Fill your spray bottle with HOT water (don't worry, it will be only slightly warm when it hits him). Spray him for about 5 or 6 seconds then wait a few seconds, then repeat. This may stimulate him to do the "eye cleaning thing", which is a natural behavior. It involves him popping his eye out of it's socket and rubbing it with the inner muscle. It looks very wrong, but it is normal, healthy behavior. This is how he cleans it. He may just have something in his eye and this may help clear it. If he never gets the stimulation, he may not be cleaning his eyes.
He will almost certainly not perform this behavior unless he gets the warm shower.
My male Jax does this every morning when I spray him and his eyes are 100%. He seems to take advantage of the shower every day to clean his eyes. He will even sometimes rub them on a branch.
Make sure the water is warm. Cold water will probably only make him cringe or move away.
If the problem persists or gets worse, you may try flushing the eye with a saline solution, like the kind people use with their contacts. If that doesn't help, see a vet. Another possibility is a lack of vitamin A, but this is rare in Jackson's.
good luck.