[AnimalMuppet]

Depends. If I'm hunting with a bow or a throwing stick, I'd bet stereopsis is pretty important. Do I need it? Maybe not, but I'll be more accurate with it.

If I'm running through the woods, trying to escape from a bear, stereopsis is pretty useful, because dodging trees while at a dead run is life or death.

I don't do either of those, but some of my ancestors probably did. But I play sports. I may be able to catch a ball with one eye. Getting myself to where the ball is going? I couldn't do that as well with only one eye.

So: Do I need stereopsis? No. Did the human race? Yes, it was a competitive advantage to have.

[tbabb]

> I play sports. I may be able to catch a ball with one eye

I would love to see a sports game where one team can use both eyes, and the other team only has one eye uncovered. I imagine it'd be downright funny.