Is my lizard sick , old or both?

Question
Hi there, I've had a pet lizard (Not sure what kind but I think it has yellow belly somewhere in its official name and it likes to dig underground) for I think about 5+ years now and everything with him has been fine but in the past couple weeks he hasn't been digging under his mulch like he always used to,not eating his crickets, and his eyes are always closed and when I check on him only one ever opens. It can't be anything in his cage like lights or tempature because its been the same setup since I got him and only in the past couple of weeks have I seen any problems.So is he sick,old,damaged or something else?  Please Help!

Answer
Hello Mike,

Can you send me a picture of your lizard, that would help?  You can send the picture to Drache613@tampabay.rr.com
I need to know what type of lizard he is so I can correctly diagnose the problems & address the husbandry issues.
What type of UVB light are you using?  Is it a flourescent tube light or a compact or coil light?  What type of basking light are you using?
What are the current temps now?  How do you measure the temps, with a stick on thermometer, a digital probe or a temp gun?  
What is he eating?  Do you offer him water regularly?
Do you use calcium supplementation?
It sounds like he may not be feeling well, so we need to get this figured out pretty quickly.  They can go downhill rather fast.

Tracie