Thank you for getting back to me. You've done everything right so far. The symptoms you've described often occur when a hamster is very old. A two-year-old hamster is the equivalent of a human in their late eighties. Since your hamster hasn't improved with the change of litter and increased ventilation, I suspect that you're looking at an age-related problem. Lack of coordination and swollen eyes are very common.
As hamsters get older, they become more prone to some diseases that can't be treated. Some of their organs can become embedded with minerals. They can develop cardiomyopathy and heart failure. Cancer becomes common. You can read more about hamster old age here:
If after reading about the diseases of old age, you decide that's what's wrong, all you can do is keep your hamster comfortable as possible. If he's still eating, feed him his favorite treats. In addition to wiping the eyes, you can put in a drop of preservative-free saline solution twice a day to soothe the eyes.
Even at age two, there's a slight possibility that this may be something treatable. If you want to be certain about this, you should make an appointment with a vet. If it turns out there is no treatment, and you feel the hamster is suffering, you may make the difficult decision to have a vet end his pain. These links will take you to directories of vets who treat rats, and would also be good with hamsters:
If you have more concerns or questions, just let me know by clicking on REPLY. I'm sorry not to have better news for you. It's always painful to watch a beloved pet grow old and frail.