Visual Illusions

The optics of your eyes form an image of what you see, but the visual cortex in your brain processes (or perceives) that image so you know what you are seeing.  How this processing is done remains largely a mystery, but every now and then your brain encounters images that it cannot perceive correctly.  These images, commonly called optical illusions, are more properly called visual illusions since they play tricks on your visual perception.  Here is a selection of intriguing visual illusions.