This Creepy Optical Illusion Will Wow The Kids

Every now and then we come across a trick that's guaranteed to properly impress even the most cynical of kids.  This one is a step up from the average optical illusion; done right, it'll make it appear as if you have a hole in your hand. And all you need to try it is a sheet of paper, rolled into a narrow tube. The illusion is based on something called binocular rivalry, a visual phenomenon in which perception alternates between different images presented to each eye. Turns out, looking through a piece of rolled-up paper can trick your eyes into seeing 'through' your own hand. This brilliant BrainCraft clip explains how it works. Give it a go and spend the weekend freaking out every child you meet. https://www.youtube.com/watch?v=jCbgWNOZzYo