The human brain plays tricks on our perception and can be bewildered by certain visual illusions. This document presents several optical illusions through images and instructions, such as apparent motion of dots or a spiral pattern that may appear circular, in order to demonstrate how the brain perceives things differently than how they really are. Following instructions to stare at dots and then look at a wall, one may see an afterimage or illusion of a face, showing how the brain fills in information.

1. The human brain …
… tricks us when it can!

2. If you think something is rotating – go home
you need a break

3. If you want to trick and bewilder your brain…
… you should look at the following pictures

4. It ...

5. … doesn’t move!

6. ... Parallel or not?

7. Spiral or cirkles?

8. Concentrate on the cross in the middle, soon you will see
the moving dot becoming green!
Keep looking at the cross
and you will notice that all
the dots except the green
one will disapere.

9. The best for last...

10. Follow these instructions.
1. Find the four vertical dots in the middle.
2. Stare at them for 30 seconds.
3. Then focus on a wall about one meter away.
4. You should see a bright spot.
5. Blink a few times and you will see a figure.
6. What do yo see?? Or ... Who do you see??