I once tried this method on a close friend of mine. It was April Fools, and his mom came in the room while I was doing it and laughed. I smiled and clapped my hands when I was finished. Of course I fixed it the next day, but I do admit that having balls for eyes is something everyone should try to do, even if it's on another person. He told me he could see a different universe. His children were waving at him.