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.

In this video, I explore my fascination with magic and optical illusions by building five furniture chair optical illusions. Each design is revealed with a detailed explanation of how they work. The ...

At first glance, this pen trick appears to defy logic, creating the illusion of the impossible through nothing more than precision and timing. Sleight of hand transforms an everyday object into a tool ...