This without a doubt one of the best illusions, I have seen so far.
Follow the instructions:
1 - Relax and concentrate on the four small dots in the middle of the picture for about thirty seconds.
2 - Then, take a look at a wall near you (any smooth single colored surface).
3 - You will see a circle of light developing.
4 - Start blinking your eyes a couple of times and you will see figure emerging...
5 - What do you see? Moreover, who do you see?