This figure looks like a warped spiral made up of white and black squares on a gray background.  If you examine it more closely, however, you will find that it is actually made up of four concentric circles.  This illusion was first described by Baingio Pinna and Richard L Gregory in a 2002 article titled […]

Do you see a spiral in the image below? There is no spiral.  This drawing consists of a series of concentric circles.  This illusion, called the Fraser spiral was discovered by British psychologist James Fraser in the early 20th century.