I have a 1 year old Leo, Tremper Albino, male. His weight is great, tail looks huge, color is great, eating and interacting well with us. Recently noticed he has been a little lethargic but attributed that to the cold weather. Temp in the viv is 95 the hot side and 72 in the cool side and is controlled by a thermostat on a heat pad. There is a moist hide on the cool side and 4 hides spread across the tank from the warm side to the cool side. Substrate is a shelf liner with no adhesive. As soon as I noticed the lethargy, he started holding his right eye closed. He opens it some times like when he eats or we hold him, but notice that it is closed as soon as he is comfortable. No puss, no swelling, not sunken in..... why is he holding his eye closed? Please help.