Paul McCartney says that performing “eye yoga” has helped his vision over the past 20 years. “I learned off some yogi in India. He explained that your eyes are muscles. Your ears aren’t, so you can’t exercise your ears. But your eyes, you can. So head still, and then you look up as far as you can, one, two, three, go back to the middle, then down, back to the middle. You do three lots of that, then go to the left and the right. Now, you’ve got a cross, up and down, and sideways, now you do the diagonals. It all makes sense. I don’t know if that’s why I don’t need glasses when reading a newspaper.”