Sure, sure. Not nice, just looking out for yourself.

[ Maybe that's even what it is, but still... Cain likes to think the best of people. Surely it's not only self-interest at play. ]

But that's besides the point. It shouldn't be that hard to test things. Just see how far away you can read something, test how easily you can distinguish between smells, that sort of thing. There's lots of simple tests we can do.