Motion Induced Blindness
If you look at the image for about 10 seconds, focusing on the flickering green dot, one, two, or all three yellow dots will disappear. Well, they won’t really disappear, they’ll still be there, but you just won’t see them anymore.
This is called motion induced blindness, a perceptual illusion studied in the field of cognitive psychology. The main cause of this perceptual illusion is still debated among scientists, but the effect is clearly cool.