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Purpose: To study the prevalence and risk factors of myopia with data from a questionnaire study conducted in 1983 among Finnish school children. Methods: School children (n = 4 961) from the 1st, 5th and 8th grades of school (7‐, 11‐ and 15‐year‐olds) in Central Finland were screened for vision followed by a questionnaire, which was returned by 4 352 (87.7%) participants. Myopia was categorized based on the questionnaire. Items concerned daily time spent on near work and outdoor activities, excluding time spent at school, watching TV and parental myopia and the associations of myopia with these factors were studied. Results: The prevalence of myopia was 3%, 15% and 27% among the 7‐, 11‐ and 15‐year‐olds, and if daily near work at home was ≤1 hr, myopia prevalence was 0.5%, 3.3% and 17.6%, respectively. The adjusted risk of myopia for each daily near work hour was OR 1.476 (95% confidence interval 1.099–1.984, p = 0.010), OR 1.346 (1.170–1.584, p < 0.001) and OR 1.206 (1.076–1.352, p = 0.001), in the 3 age groups, respectively. The adjusted risk of myopia for each daily hour spent outdoors was OR 0.764 (0.648–0.900, p = 0.001) in the 11‐year‐olds and OR (0.840, 0.743–0.950, p = 0.005) in the 15‐year‐olds. Outdoors time prevented myopia at different levels of near work, although less at the highest levels, and near work increased risk of myopia with the level of outdoors time. If the ratio between near work and outdoors time was ≤0. 5 or >1.5, the prevalence of myopia was 1.4% versus 5.6%, 6.3% versus 24.7% and 15.9% versus 36.9%, among the 7‐, 11‐ and 15‐year‐olds, respectively. The higher prevalence of myopia among the 11‐ and 15‐year‐old girls than boys was explained by more near work and less outdoor time among the girls. Having two myopic parents roughly doubled the risk of myopia compared to if one myopic parent in the 11‐ and 15‐year‐olds. Conclusions: Myopic parents, greater near work time, less outdoors time, a higher near work/outdoors ratio, and being a girl increased the risk of myopia. Myopia was rare in the 7‐ and 11‐year‐olds if daily near work at home did not exceed one hour or if the near work/outdoors ratio was not higher than 0.5. Outdoors time was associated with the prevalence of myopia at all levels of near work, although the association was weaker at the highest level. [ABSTRACT FROM AUTHOR]

Purpose: To compare 3‐year myopic progression between Finnish and Singaporean children. Methods: Myopic progression was compared between 9‐year‐old (mean age 9.7 ± 0.4 years, n = 92) and 11‐year‐old (mean age 11.7 ± 0.4 years, n = 144) Finnish (Finnish RCT) children and Singaporean children matched by age and refraction (SCORMMatched, n = 403) and 7‐ to 8‐year‐old Singaporean children matched only by refraction (SCORM Young, n = 186). Spherical equivalent (SE) was between −0.50 and −3.00 D. Refraction with cycloplegia was controlled annually for 3 years. Information on parental myopia, mother's education, time spent on near‐work and outdoor time was gathered by parental questionnaire. Results: Three‐year myopic progression was −2.08 ± 0.96 D and −1.30 ± 0.69 D in the Finnish RCT and Singaporean SCORM Matched 9‐year‐olds, respectively, and −1.34 ± 0.78 D, and −0.52 ± 0.44 D in the 11‐year‐olds, respectively (p < 0.001 between all groups). Myopic progression was fastest (−2.69 ± 0.89 D) in the SCORM 7‐year‐olds and similar between the SCORM Matched 9‐year‐olds and Finnish RCT 11‐year‐olds (p = 0.55). The Finnish RCT and SCORM Matched children showed significant differences in both daily near‐work time (1.8 ± 1.0 versus 3.4 ± 1.9 hours per day, p < 0.001) and outdoor time (2.6 ± 0.9 versus 0.5 ± 0.4 hours per day, p < 0.001). These differences did not, however, explain the differences in myopic progression between the groups. More time spent outdoors was associated with less myopic progression in the Finnish RCT (r = 0.17, p = 0.009) group only. In the whole materials, greater myopic progression was associated with younger age at baseline (p < 0.001), younger age was associated with mother's higher education (p < 0.001), and mothers higher education was associated with myopia in both parents (p < 0.001). Conclusion: Age at baseline was the most significant factor associated with myopic progression. However, at the same age and with the same initial refraction, the Finnish and Singaporean children showed different myopic progression. This result remains unexplained. Thus, age of myopia onset should be considered when comparing myopic progression between different samples and conducting treatment trials. Parental myopia may be a weak indicator of heredity of myopia. [ABSTRACT FROM AUTHOR]