This sounds like total quackery. The muscles controlling focus are smooth muscle*. That means it can't be exercised, it doesn't get bigger/stonger with use. It

This sounds like total quackery. The muscles controlling focus are smooth muscle*. That means it can't be exercised, it doesn't get bigger/stonger with use. It also doesn't get tired, which is fortunate since it's basically working all day. Anything purported to "exercise" your eye into better vision is either outright sham or probably teaching you to recognize fuzzy things better. * Quick review: you have three types of muscle: skeletal, smooth, and cardiac. Smooth muscle lines round things: arteries, intestines, iris, lens, etc.