You want to see a hole in the center of your hand without feeling any pain?
No, it is not a trick of fakirs, nor is it a disease associated with insensitivity to pain. It is simply a curious optical illusion, proposed and explained by Vanesa Hill on his YouTube channel, called BrainCraft.
If you want to do it or surprise your friends and family, you just need a paper tube rolled up. Then place your hand in which you want to see the hole some five centimeters ahead of one of your eyes as you look through the tube with the opposite eye. It is very important that you focus your attention inside the tube for about 10 seconds. From that moment you can see how a hole in the center of the hand. No, the hole isn't really there, but you're not crazy either.
What is the reason for this optical illusion of the hole in the hand?
As it explains Vanesa Hill In the video, the cause of the hole's appearance is based on a phenomenon called binocular rivalry. Usually, when we focus our eyes on an object, the images that come to us from each eye are similar, so our brain takes both to create a three-dimensional vision.
However, if they are totally different, as in this case (one hand and the inside of a paper tube), focuses all your attention on one, which we will call dominant, eliminating the other. Having focused all our attention on the tube, it will be the vision of the hand that is blurred, but it does not disappear completely, but the dominant image overlaps above it, giving rise to the black hole, which is nothing more than the hole of the tube.
Of course, if you choose to surprise your friends with this optical illusion, they will have to do all the steps. What are you waiting for? Start rolling those sheets up.