Got my buddy a new cage today

fun toy ideas: some rats like a wheel, some don't. a solid (not wire) plastic wheel is good, 12", a wodent wheel or kaytee silent spinner. besides wheels handmade toys are great. you can put a treat inside a toilet paper roll and tie paper around it. anything that makes them work to get treats tends to keep them occupied. you can look up how to make bird toys and parrot forage toys and it's all the same for rats. mine love to destroy cardboard and make their own nests. anything they can destroy.
he might not be exploring yet because it's all so new, maybe the eye does hinder him or make him more cautious. i would suggest keeping food and water at the bottom level where he can always get it, and a hide down there for him too.