A few weeks ago, my black bear hamster had blood in his eye and then a few days ago I noticed a gray/blue color in his eye. I asked my mother what she thought it may be and she said a cataract. Is there any way to be 100% sure it is a cataract and not just an infection?

Optional Information:
Age: <1; Male; Breed: Hamster

Already Tried:
I can't try anything