Optical Illusions

Amazingly, our eyes perceive a yellow circle in this diagram despite the lines being yellow.

The ellipse on the right appears to be longer and thinner than the one on the left, but it is in fact the same shape rotated 45 degrees.

There are twelve black dots in this classic illusion designed by Akiyoshi Kitaoka, but due to how our neurons are concentrated in the fovea, it's difficult to see more than one at a time. Can you relax your mind enough to catch them all?

This optical illusion is driving the internet crazy! The Daily Mail reports that this "Seemingly simple optical illusion will have your brain doing somersaults." Though it seems like there are more, there are in fact only five bars in this diagram.

Which rectangle is darker? Though the one on the left appears to be darker, they are in fact exactly the same. Blocking the dividing line with your middle finger may help illustrate this devilish illusion. [h/t Boing Boing]

Which line is the largest?

Due to the structure of your eyes rods and cones (retina rods and cornea/Coriolis cones) and this pattern appears to be slowly rotating at the speed of the earth's rotation. try looking at this one in south "of the border" America!

This hazardous pit is designed to resemble an ultra-realistic 3D chalk painting.

Though one of these lines appears to be longer than the other, they are in fact the same length.

Pareidolia is a phenomenon whereby random visual stimuli, such as clouds, are psychologically interpreted as animals, faces, or other significant images. In this picture of random foliage, some people claim to see the head of Paula Deen.

Can your eyeballs resist the sky blue "Moiré Effect"?

Though not strictly an optical illusion, the Isihara Color Blindness test illustrates the variability of human perception. The numeral "82" here is clearly visible to viewers with normal color vision.

Known as "The Devil's Tuning Fork", this figure's two cylindrical prongs mysteriously transform into two bars at the opposite end.

Stare at the dot for 5 minutes. Can you see the shark?

Do you see a face or TWO faces?