Speaking on the podcast Table Manners to promote the new "Linda McCartney's Family Kitchen" cookbook with his daughters Mary and Stella, Paul McCartney discussed how he uses eye yoga to keep his vision sharp.
“I learned [it] off some yogi in India. He explained that your eyes are muscles whereas 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, one, two, three, then 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’s pretty good stuff. It makes sense, though, doesn’t it? It makes sense if they [eyes] are muscles...I don’t know if it means that that’s why I don’t need glasses when I’m reading a newspaper. It makes sense, you know? It’s a good idea.”