https://seedmagazine.com/images/uploa...erIllusion.jpg
Stare at the red dot in the center of the figure for a minute or two. Before long, the green ring will disappear—it simply seems to fade into the white background.
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https://www.123opticalillusions.com/p...lac_chaser.gif
Stares at the cross for about 20 seconds or so. And you will se what happens.