The flickering circles in this video appear to wander around randomly.  The circles are not moving (just flickering), but the shapes seem to drift whenever you do not look directly at the circles.  You can frame the circles with lines and they will still appear to move.  It is interesting to note that the more circles you add, the more motion is perceived.

This optical illusion was created by Christopher Blair, Lars Strother, and Gideon Caplovitz from the University of Nevada, Reno.  It is a finalist for the 2015 Best Illusion of the Year Contest.

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