You need to get it to the vet and let them have a look and they can advise you on what to do. It sounds like an infection to me.
What's Wrong With My Hamsters Eyeball ? I Saw Its Eye Ball Is Huge And Freaky Looking . What Can I Do?
It probably bruised it's eyelid it will get better
Gey well I have a dwarf hamster and all hamster have big honking eyes my does here I will put a picture of here well it depends how big they are go to vet if they get big (bigger)* hope this helps re: Look at pic 
There is certainly nothing wrong with your hamster eye its a dwarf hamster its eyes are just big and the are a meaner than syrian hamsters and they are fairly light