Have there been clinical studies of doing this to correct eyesight? A few years ago I would hear radio ads, which struck several of my snake-oil buttons, and th

Have there been clinical studies of doing this to correct eyesight? A few years ago I would hear radio ads, which struck several of my snake-oil buttons, and they've totally disappeared from the radio, which presses a few more. (Because I'm feeling kind I won't even make you groan by asking if the studies were double-blind.)