Optical illusions and teasers

This page contains a number of optical illusions to tease your mind.

The squares marked A and B are the same shade of gray.

See the original web page for an explanation of what's happening here.

This is similar to the above.

In this case, the green and the blue, in their respective spirals, are the same color. Exactly. It doesn't look that way to me, but it can be demonstrated in a couple of different ways. See:

• Color Illusion
• Your Eyes Cheat Your Brain
• The best optional illusion I have seen all year
• The blue and the green

This math puzzle, obtained from http://www.briandela.com/files/picture.gif, is very interesting. Note that this works even if you print this, cut out the pieces, and do it on your desk. Or even if you make your own pieces with the appropriate dimensions.

Count the black dots in the above image. This came from http://www.bigjuju.com/jokes/blackdots.htm

This came from http://www.bigjuju.com/jokes/focusonthedot.htm

This came from http://www.bigjuju.com/jokes/lines.htm

This came from http://www.bigjuju.com/jokes/eyeonthedot.htm

This came from http://www.bigjuju.com/jokes/colourconflict.htm

This came from http://www.bigjuju.com/jokes/elephantlegs.htm

Other places

• Curve ball
• Illusion Contest
• Lightness Perception and Lightness Illusions
• Google search

Written by: Dave Regan