Look at any single white dot in the picture above. Shift your attention to a dot thaat seems to be black or gray, and you'll notice that it's actually white. Then move your eyes around the picture. What seems to happen to the dots?
Without measuring, see if your eyes can tell on which pyramid the dot is exactly halfway between the top and the bottom. The dot is exactly halfway between the top and the bottom on pyramid A.
How many different colors do you see in the image above? Are there two different shades of blue, or just one?
Look at the center of each flower above. Is one center circle larger than the other, or are they the same size? Many people think the center dot on the left looks larger, but the two flower centers are exactly the same size.
Are the lines between these rows of blocks straight or sloped at the ends? Check them with an edge of a sheet of paper to find out if you're right.
What do you see in the middla of this picture? Some people see a B, as in the horizontal A, B, C. Others see a 13, as in the vertical row 12, 13, 14.
Courtesy of Highlights for Childdren <www.Highlights.com>