Optical illusions are fantastic for just plain screwing with your mind. Take the image below posted by Will Kerslake.
What do you see? One, two, or maybe even three black dots dancing around the grid.
In fact there are twelve dots in this static image but our brains can't seem to get focus on them all at the same time. Why? I'm no scientist so I really don't have any clue but it sure is fun to watch those dots dance.
There are twelve black dots at the intersections in this image. Your brain won’t let you see them all at once. pic.twitter.com/ig6P980LOT— Will Kerslake (@wkerslake) September 11, 2016