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A head-scratching optical illusion challenges the perception of color and how the brain plays tricks on us. In an image created by the UK contact lens vendor Lenstore, a series of lilac letters ...

A study of mice starts to unravel how the brain gets tricked by this kind of optical illusion, and it gives clues about how visual perception works. Optical illusions play on the brain's biases, ...

Optical illusions play tricks on your brain and can make you see things that aren't really there, from static images swirling around the page to images that stay with you even after you look away.

Optical illusions are older than you think. The first optical illusions date back to 20,000 BC and took the form of cave sculptings. Nowadays they are found all over the place – on screens, in books ...