Look at the black dot in the center of this image and move your head closer to your screen and then back again.  Do the outer circles appear to be moving? This illusion, known as the Pinna illusion, was the first visual illusion to show a rotating motion effect.  It was discovered by Dr. Baingio […]

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.