Optical Illusion 1

Optical Illusion Galleries

Is the following object physically possible?

How many prongs does this fork have?

The green is identical throughout this illusion.

Try to count the number of black dots on the image below...

This is an example of an anamorphic illusion created by Julian Beever.
This sidewalk drawing was drawn in a special distortion in order to create an
impression of 3 dimensions when seen from one particular viewpoint