This paper tests whether the use-abuse theory or the biological theory of myopia explains the appearance and progression of myopia among 12--17 year olds in the United States. The use-abuse theory predicts that current amount of reading and cumulative exposure to reading, as indicated by years of schooling, explain myopia. The biological theory predicts that either age from birth or age from puberty explains any tendency for myopia to appear and progress among children or adolescents. Regression analysis shows that education explains all the tendency for myopia to appear and progress among 12--17-years-olds. When we control for education, age is not related to increased myopia. Myopia progresses, on the average, 0.22 D per academic year. However, education explains only a small fraction of the variance in myopia.