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 ...

A viral painting appears ordinary at first, but many viewers claim a face emerges after prolonged viewing. Neuroscience ...

Optical illusions occur naturally in different habitats and conditions across the world. Cloud formations can sometimes make it seem like there's an ocean or a UFO in the sky. Whether it is salt flats ...