Have you ever watched something disappear while it is still there? Fix your eyes on a point, and stationary images in your peripheral vision may fade after a few seconds. This illusion, called Troxler’s fading, was first described in 1804 by Swiss physician Ignaz Paul Vital Troxler. It happens because our sensory neurons adapt to unchanging stimuli: when nothing changes, neurons stop firing and the brain filters the information out. A simple experiment – drawing a colored dot inside a ring and s