Well I ran into the same problem with my Ambilobe male.. and it happened right after he had a major shed, eyes included so.. I suspected that perhaps a tiny piece of skin got in the eye or was not completely off the eye.. He had his one eye shut for about a week as I watched to see if it would correct itself on it's own.. he didn't seem to be in any sickly health and was still eating and drinking fine.. there was no discharge either.. So..I assumed no infection had set in yet and I didn't want it to.. I did my own research online as what the best thing to do and all "signs" pointed to giving it a light rinsing with some kind of clean water/saline.. Well since my Cham drinks and gets sprayed with Distilled water which is very pure everyday anyway.. I decided to rinse his eye twice a day I had my grandfather hold him while I pried his lid open gently the best that I could and I did this light spray into the lid area for a few days.. you don't want to spray it strongly.. be very gentle if you decide to even try this..A vet would more than likely have done the same thing..Well within the second treatment he had the one eye open on various occasions for short periods of time.. then it was closed again so I did a third treatment and by then once his eye was all dried out from the spraying he had started to open it again to where it became good as new.. so my guess is perhaps a little piece of debris could have gotten in your chams eye.. and maybe it just needs a rinsing.. ? BUT I am no expert so.. only take my advice on your own free will if you think it is something that might work for you..best of luck!