August 2010 Puzzle
August 2010's head-scratching puzzler
Here's another optical illusion. To learn why this illusion occurs, click here or scroll down.
The squares that have been drawn on the background pattern may look as if they have been bent, but in actual fact they are perfectly straight.
This is an example of the "Zollner effect." It shows how straight lines appear to bend if they intersect with or are seen against a background of curved lines or lines drawn at different angles. This strange effect occurs because your eyes and brain work together to try to make the straight lines fit into the background pattern.