How do we see in 3 dimensions?

Question

How exactly are we able to see in 3-D? As far as I know, all "seeing" is light hitting our eye. Light hits an object (say, a wall) and bounces off. That light then travels and hits our eyes. That means we arent "seeing" the object, rather just the light hitting our eye. It seems to me, then, that we shouldnt have any depth perception. Everything we "see" should be right in our face, taking up our entire view. Because the light is touching our eyes. How exactly do we get depth in our visions when all we are seeing is light that is directly touching our eye? I hope that makes sense...

Answer 1

This is why we have two eyes.
The brain composes a three dimensional model of the surroundings by taking the different images from either eye and superimposing them in such a way to make us have depth perception.
This can be tested by covering one eye and trying to reach a distant object with your hand or by estimating its distance away from you. Sitting in your chair, try and touch the computer screen with one eye covered or closed. You will find yourself unsure of when you are about to touch the screen and this is because you do not have enough information to make a full model of the surroundings

Answer 2

Yes, we are able to see because light is able to enter our eyes...this is the path that the light rays pass thru: bulbar conjunctiva > cornea > anterior chamber > pupil > lens > vitreous humor > retina > optic nerve > optic chiasm > optic tract > occipital lobe of the brain. The retina is the one mainly responsible for seeing, the information transmitted by the nerves to the brain for processing and interpretation. We are able to have depth perception because of our two eyes. Each eye has its own field of vision, that's why you are able to see with the other eye when one is closed or occluded. These 2 fields of vision overlap when both eyes are open and the brain processes these visual fields as one single vision. The retina has 10 layers of cells and one of those layers contain photoreceptors (specialized cells called rods and cones). I think these also help in depth perception. Rods are mainly responsible for light perception while cones are for color vision. The rods are most sensitive to light and dark changes, shape and movement and contain only one type of light-sensitive pigment. The cones are not as sensitive to light as the rods. However, cones are most sensitive to one of three different colors (green, red or blue). Signals from the cones are sent to the brain which then translates these messages into the perception of color. Cones, however, work only in bright light. That's why you cannot see color very well in dark places. So, the cones are used for color vision and are better suited for detecting fine details.

Answer 3

OK.... Dude what was that? We see by opening our eyes and the rest is ..well done by its self. You don't have to get in the thing of " light hitting our eyes and "seeing" is just light hitting us and bouncing ." And yes light touches our eyes.And if you want to see in "3-D" Go see "Meet the Robinsons" I think I heard that has the 3-D glasses and that kinda helps... I think?

Answer 4

You're assuming we have just one eye, which of course we don't. We have two (obviously) and with the information they gather, the brain basically uses both of the images given to form a 3d representation of what both eyes see. In other words, both eyes have different perspectives on the same thing, and the brain uses both perspectives to determine distance relative to other objects.

Answer 5

It's because we have two eyes that are spaced apart. Cover one eye and you'll lose depth perception.