Do humans have 2D or 3D vision?

Answer 1

- 1st Response: Humans do not have 3D vision - we have 2 eyes both of which see a 2D image. The combination of two lenses a marginal distance apart gives us depth perception; this gives us an illusion of 3D vision; if we had true 3D vision then we could see the "back" of the object we were looking at.
- 2nd Response: Humans absolutely do have 3D vision and the fact that they have 2 eyes has no bearing on 2D vs 3D. Humans can see three separate dimensions, length, width, and depth (though they infer this depth from the dissonance between the other two images). Depth perceptionoccursat about 6 months of age (sometimes sooner). If you are looking into a room, you can see the back of the room as well as the L x W dimensions. And yes, we can see the back of an object as long as the surface is transparent or translucent.

- 3rd Response: Humans do not have 3D vision. Seeing in 3D does not mean you can see the back of an object. It's hard to explain something impossible (for example a tesseract), but if you were to have 3D vision then you would be able to know the length of how far back something goes without using any of the attributes given off of 3D objects (shadows, seeing the curvature due to each eye having a different type of lens, etc.). For example Look at the closest wall to you, without any other knowledge but what comes from looking at it, how far back does it go? What if it is transparent? Okay, doesn't really matter. Go to a glass box, sit down next to it, and without using information given from the attributes given off by 3D objects figure out how far back it goes. You can't
All your seeing is an image produced by signals in your brain. It's like a tv or one of those special cameras that allow you to see things in "3D" because they have both types of lenses your eyes have. It looks 3D, but take the picture, and then look at the screen, is the image on the screen 2D or 3D? 2D, that is exactly how humans see things.