The latest visual illusion to make me question my reality is a blurry swirl of colors that disappear if I stare at them for long enough.
The illusion popped up on the r/woahdude Reddit today. But versions of it have existed since at least 1804, when a philosopher named Ignaz Paul Vital Troxler described how an image can fade away if you stare at it hard enough. For me, the image disappears almost entirely, until I realize it — then it snaps back into focus.
The reason the colors disappear is because the brain stops paying attention to visual scenes that don’t change — which isn’t normally a problem, Derek Arnold, a psychology professor at the University of Queensland, tells The Verge in an email. Usually, movement in the environment...
