Try making a 3-D hand drawing. It’s easier than you think and requires no special artistic skills.

Optical illusions are fun ways of tricking the brain. Some of them cause us to perceive movement when their is none, others cause us to see something as being far larger or smaller than it really is, ...

So far it's mostly been adults who've had the fun of using 3D pens, which is ironic given how drawing in mid-air can release your inner doodling child. However, the 3Doodler Start is a 3D pen from ...