According to this text, a small proportion of myopia is familial. But the prevalence of myopia has been increasing over the past 50 years, and has been associated with increased education and urbanization--the prevalence of myopia in rural East Asian areas is low...http://w3.csmu.edu.tw/~pcl/handout/optometrynews/How%20genetic%20is%20school%20myopia.pdf .
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