10 Mind Melting Illusions (And Exactly How They Work)

4. False Colour Image

Stare at the dot in the centre of the image and after a while, it will appear to flip back into true colour but once you begin to move your eyes you see that it's actually in black and white.

Just to shake things up a bit, this is less to do with your brain playing tricks on you (although it is a little bit), and more to do with the light receptors in your eyes.

Despite the spectrum of colours that you can perceive, your eyes can actually only detect red, blue and green light. This means that anything else in between is made by mixing those colours together, much like the pixels on a screen. These receptors, however, can get tired of you overstimulate them, leaving the others to pick up the slack. The result is that you will see the complimentary colour for a short time afterwards.

In the image above, for example, the blue receptors get all tuckered out from looking at all that blue, and as red is the "opposite", you will see reddish hues as you temporarily become blind to the colour blue.

This is an optical illusion, insomuch as seeing any colours at all are optical illusions - it's just the way your brain processes different wavelengths of light after all.