Why is the ability to perceive depth more than a matter of visual acuity?

Question

Why is the ability to perceive depth more than a matter of visual acuity?

Answer 1

because your brain involves all your senses in estimating and calculating a depth or distance of an object or space: i.e. the surrounding environment envolves all your senses. resonating noises, smells and tastes (the brain somewhat combines the latter two of these almost instantaneously), and any touch related data all combine with what you've already visually observed. for example, you see a well made of brick and whether you have touched the bricks or not, you know they are hard and used to build reasonably large structures in need of ample strong support. you also understand the function of a well which helps you paint a mental picture as to it's depth. if you've never heard of a well before your curiosity may cause you to draw nearer to the well, smelling the dampness, feeling it on your skin making your hairs stand on end. perceiving the danger, you may instinctively/cautiously take a step back finding a secure place to peer from and into the well. you can see that it's deep, but it's hard to perceive exactly how deep. so you may throw a small stone into it to get an idea of it's dimensions. doing this, you'd hear the resonating sound and listen for the final splash, probably either counting, or at least approximately noting the seconds before it reached the water below. the same is true for acurately percieving the depth of any space. we use our senses and surrounding objects to measure distance some examples of these are resonating noise, and faint to potent smells, knowledge of environmental elements to draw conclusions on depth and calculate an approximation (i.e. building/surface materials or items within the space, color, or surface/angle variations, etc...) on a primarily subconscious level in combination with what we've already visually observed/perceived.

Answer 2

Depth perception involves not only a 2 dimensional correlation of the images from 2 eyes, to figure out what parts of those two images match up, it involves hypothesizing what sort of three dimensional objects would produce both the correlations and differences that those two images have. Sometimes the hypotheses are wrong, and the system can be fooled (search optical illusions). Sometimes several different 3 dimensional hypotheses are scored about equally, and the perception is a rapid flutter between those possibilities, and sometimes no reasonable hypothesis presents itself and the perception loses 3d, altogether. Think about those 3D images made of dots that just look like a bunch of dots or picture fragments on a flat surface until you get the spacing between eye and paper just about right, then a 3D image pops out at you.

http://www.magiceye.com/



Perceiving 3D from two 2D images is an elaborate guessing game. Throw in motion and it gets more complicated, since playing the game has to keep up with the changing images.



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Regards,



John Popelish

Answer 3

The perception of depth requires the ability for your brain to have some method of determining distance to an object in your eyes' field of view. Simply having a high level of acuity is insufficient, if say you had only one eye.



Nature's way of solving this problem was the evolution of binocular vision: with visual cues from a single source arriving at two receptors (your retinas), your brain does the processing that allows a person to sense the different distances to objects in your field of view as depth.



The same principle is applied in such optical devices as rangefinders and robotic vision systems.



The military has also investigated the use of such passive optical methods for determining target range in fuze/warhead design for airborne missiles.

Answer 4

20/20

Answer 5

Because

Answer 6

http://en.wikipedia.org/wiki/Visual_acuity

http://en.wikipedia.org/wiki/Depth_perception