If depth perception works because the brain checks the difference in the position of the object between the two eyes and concludes how far away it is, how can we still see depth when one eye is closed?

Question

If depth perception works because the brain checks the difference in the position of the object between the two eyes and concludes how far away it is, how can we still see depth when one eye is closed?

In: 3602

Answer 1

Neural networks, your brain creates a model of the world and constantly checks that model against reality.

So for instance, say I see a stop sign up ahead. I’ve already seen many stop signs, so my brain already has a pretty good idea of how big it should be. If only one eye is open, the brain can’t directly measure depth, but it can use those estimates based on how big I know a stop sign should be in order to approximate how far away it is.

And honestly, 99% of the time you don’t need full information, because the estimates are usually pretty accurate – however, optical illusions exploit this knowledge to have your brain create a mental image that isn’t actually there.