I don't know. But studies have shown that myopia develops in children who don't play outdoors very much, and does not develop in children who do spend a lot of time outdoors (people used to think it had to do with reading books).  Late-onset myopia (e.g. in your 20s/30s) tends to develop from heavy computer/screen usage where you  don't refocus your eyes and just look at the same distance object for long periods of time.  The best thing for your eyes is to  look at things off in the distance, either by going outside, or putting your computer in front of a window so you can keep looking into the distance (not sure that has been studied though). You can also get some glasses looking things that you flip which go from +2 to -2 or something to force you to exercise your cilia muscle (the one bending your lens and focusing), not to make it stronger but to stop it from spasming.

Myopia is caused by your eyeball growing longer. It is not about muscles being weak . It is not going to grow shorter. Wearing glasses could make it worse, yes, but I don't think you can make it better by eye-exercizing yourself out of the condition. Once you have it, you have it for life. Most people wear the glasses because they want to see clearly, even if it gets worse, because they can always just get a new prescription and continue to see clearly.