Psychedelia 2 Painting

It is not clear how phosphenes originate in our visual systems. Perhaps the best current theory points out that our eyes and brains are living things, and thus always active. This activity generates "noise." Stuff going on no matter what. In the absence of external stimulation, spontaneous illusions become obvious, and appear to us in the form of visual illusions, or hallucinations. They appear as moving and flickering lights, and even broad areas of color. They do not appear random, like the "snow" that used to appear on analog TV channels when nothing was being broadcast, but more "chaotic." Perhaps it is our brains attempting to make sense out of non-sense. One of the best known phosphenes is the so-called "bagel illusion," which is the display Salvador Dali famously talked about inducing by pressing on one's closed eyelids. It is also familiar to migrane sufferers. Bagel illusions appear to varying degrees, from small patches off center in the visual field, to full-blown, blindingly bright circles visible with open eyes. They can be so bright as to block vision in full daylight! Here we see a partially formed bagel illusion appearing as a bright ruddy crescent at the bottom, with only a greenish hint of the illusion's top half.