Optical Illusion

(I saw an article in Yahoo today , that made me think to post about the topic.. Read through the bottom as there is a little mind test for you there. )

An optical illusion (also called a visual illusion) is characterized by visually perceived images that differ from objective reality. The information gathered by the eye is processed in the brain to give a percept that does not tally with a physical measurement of the stimulus source. There are three main types: literal optical illusions that create images that are different from the objects that make them, physiological ones that are the effects on the eyes and brain of excessive stimulation of a specific type (brightness, tilt, color, movement), and cognitive illusions where the eye and brain make unconscious inferences.

Whether it’s an optical, physiological or cognitive illusion, the design plays a trick on your eyes (and mind). Check out some of the interesting illusions below—but beware, you may not be able to absorb them all in one sitting.

FLOWING LEAVES
The brown leaf shapes against a green background make this look as if the entire group is flowing—making waves if you focus on the picture as a whole.

PULSING VORTEX
If you stare at the image for long, you'll notice a fast pulsing vortex..

HYPNOSIS
Although this image is comprised of simple purple and green squares outlined in black, it looks like it is bulging out in the center

BULLS-EYE
If you stare at the center of the image, it looks as if the outer rings are rotating in alternating directions—an effect meant to mesmerize the viewer

Optical illusions are actually tricks to the eye. There are images that can be misleading to the mind perception. Now, I got a photo here and I myself was mislead by the illusion I have found in here. . It's a dirty Minded test. It might give you a clue. I won’t talk any further, chances are I could ruin the illusion for you accidentally.

Don't be shocked once you discover it, It's not what you think.. LOL

Did you find out the Illusion?