First of all, it' not comparable with a spider, they operate in totally different ways and the species are not even remotely related. Second of all, tarantulas are generally not blind at all. They just mostly rely on other senses, but they are not blind.
About the dividing project: I know Cheri have a divided tank, but with different dart frogs. Perhaps she could shed some light on this project for you. I personally have no knowledge I'm affraid.