It may sound like an utterly rudimentary question, but Why do things look smaller from farther away? What mechanism is at work that makes this so? I found one explanation that stated, "because the reflected light from the objects occupies less space on your retina," but that's no better than saying, "they look smaller because they appear smaller." I understand the theory of perspective, how to represent it, but I'm very curious to know ...
What is the mechanism that causes objects in perspective to appear larger or smaller?