OPTICAL ILLUSIONS

If you keep your eyes on the pink dots while they rotate, you will see only pink dots, whereas if you look at the black +  in the centre, they will turn to green. (this only happens to people who come from intelligent families)

Depending on how you look at the above picture, you will see ’optical’ or ’illusion’.

To stop the dots from moving, stare at one of them for a few moments, and the movement will stop.