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 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 ...

The Best Illusion of the Year contest offers researchers, and participants, an opportunity to explore the gaps and limits of human perception. By Katrina Miller Take a look at this video of a waiting ...

This is the amusing moment an awesome optical illusion fish tank made it look as if a cat was inside. The pet-loving owner bought the custom-made glass aquarium for Milo, the Persian feline, and her ...

When looking at this patch of lawn head on, it looks like a sphere just sitting in the middle of the plaza at Paris City Hall. But it isn't. Look at it from the side and you realize that it is just ...

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 ...