[souffle]

Hi there - I'm afraid he doesn't look well at all as the ears back and eyes half shut and sticky are a sign however his abdomen is very swollen there. This could be a tumour or it could be from fluid gathered in the abdomen from another cause such as kidney or heart failure. At this stage there is unlikely to be anything a vet could do for him sadly. If you feel he is still able to do hamstery things then you can let him be but he needs very close monitoring as he may be in pain and may go downhill very suddenly. He is quite an elderly hamster and these things are more common in older hammies.
It's never easy but I always think it's better a day early than a day late when he may be in pain. I hope he gives you a little more time with him in comfort x