This Vision Experiment Resolved a Centuries-Old Philosophical Debate

Imagine you are looking at a manhole cover a few paces away on the street. It looks circular, but this is because of some impressive perceptual machinery in your mind. The pattern of light in your eye, on the retina, is, of course, in the shape of an ellipse. The reason we see a circle, when the eye gets an ellipse, is because of a variety of visual cues and our knowledge of the world. How your mind does this is a fascinating process that has been explored for decades by vision scientists. ….[READ]