This brain-frazzling optical illusion is enough to put your head into a spin. The purple-and-yellow image looks as though it’s both three-dimensional and moving but is in fact stationary and flat.

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 ...

We trust our brains to do a lot. From remembering birthdays to making sure you never forget an embarrassing moment that happened years ago, we can’t avoid what it chooses to focus on — and what it ...

An optical illusion is a visual phenomenon where our perception of thinking about an image differs from objective reality. This image is seen as a high-contrast black-and-white optical illusion made ...

A grayscale ballerina who appears to be moving. A human who can fit in a doll box. A black-and-white prism which appear to change shape when viewed from three different directions. Those are the top ...

While new optical illusions go viral all the time, here are some of the most famous illusions that have kept us scratching our heads for years.

Optical illusions are a fun and challenging way that tricks our visual illusion, and this motion optical illusion is challenging for millions of people. In this hypnotic spiral pattern, a very famous ...

Add Yahoo as a preferred source to see more of our stories on Google. When you buy through links on our articles, Future and its syndication partners may earn a commission. Credit: Getty Images ...