If it is only he has issues seeing, he may be afraid to get out and run around.
I would try to make him comfortable with hidey houses, hammocks and maybe a wheel. Make sure he has lots of hay.
If you want to bond, mainly it takes time. Treats are good but not good, they will expect them 24/7 once you get them started on them. If you are trying to 'lure'' him in with treats, make sure it is palin cheerios and shredded wheat, rather than raisins. Give him the good treats. You can also get chew sticks, that has really worked wonders here!