
which of the surrounding circles labeled 1-8 is the same size as the circle in the middle of the image? Solution will be posted shortly…

Just stare at the different rings, and you should see a ton of illusory motion. That means that although there is actually nothing moving in this image, as your eyes scan around the image your brain will make you think that the rings are rotating. If you freeze your eyes and don't move them at all, you can almost get them to stop.
In this illusion you will see that all the 4 circles are expanding when you move your vision over them.
OK, this time you need to cover your right eye and stare at the black circle. The move closer to the screen and see the cross disapear. Move back again and the cross will reappear...
Now imagine the cross is a motorbike and think about them next time you go out in the car!