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 ...

Optical illusions challenge: Think you’ve got sharp eyes and a quick brain? Try this optical illusion IQ test that’s leaving even the brightest minds puzzled. This brain teaser challenges you to find ...

Everyone loves an optical illusion — even if they leave us completely stumped — and they're all around us in the natural world. From an underwater waterfall in the Indian Ocean to a surrealist scene ...