Which is perfect for finding that bag of chips in the dark. Found this gem on Boing Boing about a recent scientific study that indicates puffing a joint can improve night vision. Of course this won't help you with the "beer goggle" effect.
Their results backed up claims by the Observer columnist Sue Arnold, who suffers from retinitis pigmentosa and is officially registered blind. She noticed several years ago that drawing on strong Jamaican skunk suddenly and temporarily enabled her to see things clearly. But Ms Arnold has since warned of side-effects that could impede night-time navigation.
[Via Boing Boing]
"Only trouble was," she said, "I couldn't stand up."