Four hundred seventy-four Greek male subjects received an ophthalmologic examination and completed a questionnaire. The following were found: (1) the years of studying and urban residence are factors that strongly influence the prevalence of myopia; discriminant factor analysis classified correctly 81% of the subjects into the myopic or the nonmyopic group; (2) the incidence of myopia is significantly higher in the studying v the nonstudying groups; (3) the prevalence of myopia is higher in the more educated group; (4) there is no statistical difference between the orientation of myopes and nonmyopes toward studies or other occupations; (5) although the presence of myopia is determined by the years of studying and urban residence, the degree of myopia is not influenced to a statistically significant level by these factors; and (6) the results indicate that the interaction of these two variables is more significant in their contribution to the onset of myopia than the sum of each variable alone.