Mind the crevasse: The amazing 3D pavement art that has pedestrians on edge | Mail Online
http://www.dailymail.co.uk/news/worldnews/article-1153004/Mind-crevasse-The-amazing-3D-pavement-art-pedestrians-edge.html

Dessins de rue.

Another article that depicts some cool 3D street art.

落ちそう！

The overall pattern is a spiral shape because our brain likes to fill in missing bits to a pattern. Even though the stripes are not the same color all the way around the spiral , the overlapping spirals makes our brain think they are. The very fact that you have to examine the picture closely to figure out any of this at all shows just how easily we can be fooled.

Richard Wiseman comes one of the best color optical illusions I have ever seen.

うわあああこの緑と青、同じ色だって

Color illusion 12