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 older than you think. The first optical illusions date back to 20,000 BC and were seen in caves. Nowadays they are found all over the place – on screens, in books and even in ...

Illusions like these mess with the brain's visual processing system, making viewers see things that aren't there in reality. | Credit: Eva Almqvist via Getty Images Optical illusions play tricks on ...

Optical illusion personality tests are interesting images that trick the brain and eyes into believing what they see first, ...

It’s like putting on ugly goggles. Puzzle lovers are getting the heebie-jeebies over this “freaky optical illusion,” which makes people’s faces look hideously distorted. A now-viral video detailing ...

These mental litmus tests will melt your mind. Puzzle lovers are straining their brains trying to solve a trio of baffling optical illusions, which reportedly reveal how the viewer’s mind works. A ...

Optical illusions have a funny way of turning a simple picture into a genuine brain workout, and this one right here is no ...

Medical imaging experts are adept at solving common optical illusions, according to research from four UK universities, including the University of East Anglia. The correct analysis of medical images ...

Laeng et al., Frontiers in Human Neuroscience // CC BY 4.0 The science behind optical illusions has been thoroughly studied, but researchers are still finding new ways to trick our eyes. This image ...

Even if you have perfect vision, you can't always trust your eyes. The image above created by Lenstore illustrates this. The circle on the left appears to be a lighter shade of blue than the circle on ...