Hypothesis for cause of myopia

One of the things that I always am keen to learn more about is how to naturally improve my eyesight. Over the years I have developed a number of theories and possible exercises that I hoped would improve my vision. unfortunately none did.

According to Wikipedia, there is no definitive cause for myopia. However there are a few theories.

Genes – this is in my mind completely bogus – right now over 50% of americans need glasses to see. If our primary sense had evolved so poorly that 1/2 the population couldn’t see then we never would have made it.
Environment – The idea that the muscles in our eyes accomodate to looking only at things within 10ft from being indoors is totally plausable but difficult to do anything about.

Then I read this about the new 3D TVs. 3D video hazardous to your health

it got me thinking that perhaps looking at 3D things in 2D, like in photos or TV might train your brain to ignore depth. What convinced me more is that I can perceive things relatively close to me as flat. I’m still trying to think of ways to test this theory out.