1. Brightness Consistancy

3. Color Consistency

4. The red squares are the same color in the top and bottom of the "X".

5. shape

6. Which of the figures in the picture do you think would measure the tallest with a ruler? Don't measure -- just guess!

9. Muller Lyer Illusions

10. Poggendorf Illusion

12. Spiral aftereffect

13. “Stepping feet” Motion Illusion

15. T-llusion

16. Ames Room

17. Good vs Evil – figure ground

23. Are the horizontal lines parallel, or do they slope?

24. How many legs does the elephant have?

25. Man playing a horn? Or woman's face?

26. A rabbit, looking right? Or a duck, looking left?

29. What do see?

31. Three prong fork?

32. Is this woman old...or young?

35. Wavy Squares? No! The background of concentric circles makes the squares appear distorted.

36. Perpetually ascending staircase... how can the man go up all the time and come back to the same place over and over?

37. Stare at the Reversing Staircase Illusion until it changes to a different staircase.