today there is a pandemic of myopia . if we go to some graduate class of some university probably more than 50 percent are myopic , though some are wearing contacts or done laser . if we talk in terms of evolution or genetics , clearly these people would not have been able to function before the invention of specs , and that was may be a few centuries back . So it is not genetics but something in our environment . That that something is too much near-work for kids before around 20 years without any opportunity for the eyes to relax . We are all born with somewhat a smaller size eyeball . The body gets some feedback from the degree of accommodation from which it elongates just the right amount . I believe if kids wear weaker prescription , reduce near-work , incorporate some good habits like reading from an arms length and taking frequent breaks then myopia can be avoided or reduced . Myopia has a risk of retinal detachment , which can be fixed by laser if done within a few days . For high myopics doing strenuous work like lifting weights or running may be a risk factor .I believe wearing weaker glasses has many disadvantages , but it may reduce the progression of myopia for those kids who are prone to it.