My hamsters eye problem

[Niserya]

So this morning I found my hamsters left eye swollen and looks like it did bleed. There is nothing that is sharp in his cage or anything like that. Well we took him to a vet and they are not sure what it is either wanted us to take him to a hospital. I have got two questions if needed should I let the surgery or is it too risky. Second questions is, the vets said it might be infected my hamster stopped eating much and started to poop a lot like a week ago I thought it was just diarrhea so I didnt do much. We are nov giving him antibiotic any suggestions? Please help