Optics principles. For example, the Ames room, Hering, Müller-Lyer, Orbison, Ponzo, Sander, and Wundt illusions all rely on the suggestion of the appearance of distance by using converging and diverging lines, in the same way that parallel light rays (or indeed any set of parallel lines) appear to converge at a vanishing point at infinity in two-dimensionally rendered images with artistic perspective. This suggestion is also responsible for the famous moon illusion where the moon, despite having essentially the same angular size, appears much larger near the horizon than it does at zenith. This illusion so confounded Ptolemy that he incorrectly
The Point! inspiration for "The Point!": "I was on acid and I looked at the trees and I realized that they all came to points, and the little branches came to points, and the houses came to point. I thought, 'Oh! Everything has a point, and if it doesn't, then there's no point to it.' " The round-headed Oblio has had to wear a pointed hat since birth to conceal his "pointless" condition from his pointy-headed peers. However, Oblio is accepted in the town despite his nonconformity, until one day, when the son of an evil count is unwittingly dishonored by Oblio.