If the eye is not infected, injured, protruding, crusty, or oozing it is probably just the way he is. If it is any or all of those things, you need to see a vet.
This could mean that your hamster is sick. You should bring it to the vet as soon as possible to ensure that no infections are present. It could be a natural deformity that will do no damage, but it is best to make sure.
Same with my hamster but I think he was born like that. It's just a little bigger in size but I never noticed until today! I may be okay because sometimes things that are the same size put beside each other makes one look bigger and the other look smaller.
It could be a tumour or teeth problems (both are treatable if caught in time). Take your hamster to a vet who specialises in rodents for a checkup ASAP.
It's possible that the eye could be swollen and need treatment, or it could just be that your hamster was born that way. I would seek a professional opinion.
