Troxler’s Fading – Troxler Effect
In 1804, an interesting effect, known as the Troxler Effect or Troxler’s Fading, was discovered by Ignaz Troxler. He noticed that something strange would happen if you fixated your eyes on one particular point (see the red dot below) for about 15-30 seconds. When doing so, images in your peripheral vision (the blurry blue circle below) would fade away and eventually disappear altogether.