I don't think I believe that one.

If that was true, then siblings who are raised in the same household with the same reading habits will all have myopia. This doesn't explain cases like my household, where our son has amazingly good vision and our daughter has poor vision.

Nor does it explain my husband, who didn't need glasses until he was in his 30's (yet he read constantly). I read constantly, too, but I come from a family where myopia is very common and I can't see for nothin!

Myopia does have quite a prominent genetic link. The shape of your eye is what causes this condition, and even though being a book worm will make it worse, you can't alter the shape to much from baseline. You can especially see that this is genetic when 5 year old children have it and have to have coke bottle thick glasses. The only thing you can really do is wear the glasses or get laser eye surgery, which doesn't correct the problem but compensates by reducing the shape of the lens in the eye.