| 1. It's a simple one. How many pencils are there? There are clearly seven… what, wait! Six? No.. So how many?
2. Close your left eye and stare at the cross. As the circle moves left and right, it should pass through your blind spot and disappear completely! You may need to lean in closer to get this to work.
3. Stare at the moon long enough, and the stars should begin to fade away. How many can you get to disappear?
4. Can you tell which of these lines is longer? Test them with a ruler or a piece of paper -- you may be surprised.
5. How many colors do you see? Most people see four colors: green, blue and 2 shades of pink.
6. As the small circles intersect with the large ones, we seem to see the outlines of a growing and shrinking square. But there is no "square" -- your brain is trying to visualize in terms of solid shapes, and fills in the blanks.
7. We already had an entire post with such pictures that seem to be in motion, but nope, they aren't moving.
8. Look at the red dot for a while and gray stripes will disappear
9. Although you don't believe it, these lines are straight and parallel
10. These two birds are identical, not only in size but in color too.
11. These "fish" may appear to be wiggling, but the only thing changing in this animation is the color.
12. What do you see here at first glance? The yellow arrows pointing to the left or green arrows pointing to the right? There is no correct answer. Different people see different arrows at first (I saw the yellow ones)
13. Another "false spiral" -- actually a series of concentric circles, hard as it may be to believe. To prove that there's no spiral, try tracing your finger around one of the circles. You'll see that it never moves inward or outward.
14. Do you see the rose spots? Well, if you look at the cross, soon enough there'll only be one green spot running around, other spots will disappear.
15. First, look at the image at a close distance, then look at it from 1 meter distance
16. Hover you mouse cursor over the picture. Does it move?
17. Which direction is the cat rotating: clockwise or anticlockwise? Once again, different people will see different direction. I see it rotating in a clockwise direction. With practice, you can make it switch at will!
18. These spirals are spinning only in your head ;)
19. Three illusions in one! This three-in-one illusion includes a false spiral, an impossible Escher-esque structure, and what appears to be a seriously warped floor...
20. The word is hidden here. Can you spot it?
21. Can you tell where on this curve the lines are the longest, and where they are the shortest? 22. Are the walls of this house facing outward, or inward?
23. Which of these two dots is in the true center of the circle? 24. Can you tell which of these cars is the largest?
25. Here's a simple one. Are these two rows of squares perfectly parallel? | 
