The latest optical illusion that has captured the collective attention of the internet comes from the above image posted to Reddit’s “Whoa Dude” subreddit, which features some swirly blobs of colors that incredibly appear to fade into nothingness if you intently stare at it for a little while. As the image began to go viral, it was soon discovered that the phenomenon is nothing new, but an an illusion called “Troxler’s fading” or the Troxler effect, which was named for Swiss physician and philosopher Ignaz Paul Vital Troxler who made the discovery in 1804.
By “rigidly fixating one’s gaze on some element in the visual field,” Troxler learned that it can cause surrounding stationary images to appear to slowly disappear or fade altogether. In other words, “as we focus on a certain point in our perception field, that point becomes the main object of our visual system.”
It occurs because even if our eyes move a little when we are fixating a point, away from that point, in the perception field, the movements aren’t large enough to observe other elements. The neurons remain focused on the main object and our visual system doesn’t involve new ones for the other elements.
You can see another example in the video below: