OPTICAL ILLUSIONS

This is an interesting video about how to draw simple optical illusions with the computer. Can you do it with a pen and the rulers? Give it a try!

Optical illusion

1. Stare at the red dot on her nose for 30 seconds.
2. Turn to face a blank, light coloured surface (ceiling or wall).
3. Blink repeatedly and quickly.
4. Now... what do you see?