HI everyone! this is my (i think) 1 year old African bullfrog fumi!

as you can see here, his left eye is giving him some trouble! I noticed he has been sleeping a lot for the past 3 days. I spray him and his enclosure as much as I can since his enclosure is easy to dehydrate.
I noticed he's having some trouble opening his right eye(left in pic) and i thought that maybe there was something in his eye? I sprayed it but to no avail. He looks like he is in pain when he has his eyes shut and pulls his head into his bpdy to "curl up" in a way! I read with my partner that perhaps it could be an eye ulcer, a vitamin A deficiency? What can I do and can anyone help diagnose?

TL;DR: Something us wrong with my frogs eye, help...