Isn't this the Bates method, a pseudoscientific snake oil cure that roped in Aldous Huxley?
Mostly it focuses on learning to focus at the edge of what you currently can at a distance, and then as you improve getting lighter and lighter prescriptions. I got as far as -1.5 better, but now sit at around -1 better. Also ensuring lots of super bright outdoor environments, and focusing at a distance regularly.
Whether it's a cure or studied well, I dunno. I just encourage folks to try it out if it helps them. I have an astigmatism as well, and I haven't seen any improvement there. So definitely not a panacea.