Stereoscopic vision is a useful and subtle aspect of how we, and some animals, see. Because our two eyes both face the front (unlike some animals and insects whose eyes face more left and right), they both see similar but subtly different views. For example, if two objects are in line, one behind the other, our left eye will see the object furthest away slightly to the left, while the right eye sees it slightly to the right.
The brain is able to notice this difference, and correctly infer that the distance to the rear object is greater. Without this stereoscopic vision it would be harder to estimate how far away objects are, and whether they are moving towards us, or away.
You see this in this stereo photo of a man in a narrow laneway. The two pictures are almost the same, but the left photo (which is what the left eye would see) shows more of the lane to the left of the man (as we see it) than what the right photo shows.
Award-winning physicist Aron Wall observes that knowing God may require something analogous to stereoscopic vision.
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