Somebody said something about taste. It'd be a lot easier to do the Night Thang with the girlfriend without taste, that's "fa sho"!
But now I'm just trying to sound cool.
I think moving in a pitch black house is different than not being able to see at all. I don't really know how. If you can see, but it's very dark, it's easier to imagine the positions of all your furniture than if you just coudn't see. It's almost like your eyes can see through the dark. Maybe not, I don't know. All I know is that locomotion of any sort would be excessively difficult without sight. Sure, you'd miss out on the nice music, the happy conversations, the frustrating arguments, the soothing voice of the aforementioned girlfriend, but without sight it'd be difficult to find something to eat. What's tougher--feeling lonely 24/7 or starving because you can't find food unless you trip over it? I still think sight is far more important than any other sense except touch.