Help, my panther keeps one of his eyes shut sometime.

I noticed about a week ago that my 10 month old panther was either sleeping of had his eyes shut around 5pm. During the day he was very active going all around his 6' cage. He was eating fine and all. Yesterday I noticed that only one of his eyes was open and the left one was closed and I could see him moving the eye but it was not open no swelling but just closed, but If I were to pick him up he would open it. So I made an appointment at the vets. He said besides the eye being shut 1/2 the time we were there he looked very healthy and even said it was the strongest looking chameleon he had handled. He said to be on the safe side he was going to give him a shot of vit. D, put him on antibiotics (Amikacin 50/ml) which I shoot him up every 3 days and also a liquid (Panacur) that I inject in his mouth. He said he should make a full recovery, the bill I thought was cheap $63. I moved 2 months ago and my chams cage is closer to an airvent so at night he gets a red heat light on him. The coolest part of the cage gets to 75deg. I also ran out of the vitamins that i sprinkle on my crickets and the pet store had Reptocal which says it has vitamin D but didnt say D3. So I dont no if any of these things had anything to do with his help maybe one of you have something to say, or something I should change.

About an hour ago I saw that he had a cricket in his mouth now I he has his mouth open 1/4 of an inch and I can still see the cricket in there. The vet opened his mouth and looked in it and said he found no signs of rot. Should I be worried?