Vanessa Hill shows us how this crazy optical illusion works on her YouTube channel BrainCraft. Using a narrow tube made out of rolled-up paper, you can make a “hole” emerge in the palm of your hand.
Place your hand roughly 5 centimeters in front of one of your eyes, while you look down the tube with the other. For at least 10 seconds, try to focus on the sight in the distance through the tube and not your hand. After a while, it will appear that you can see through a hole in your hand.
How does it work? Check out the mind-bending video below: