The above linked study is from 14 years ago. (I linked it because it addressed arctic communities.) It's the more recent work has mostly ruled out the near-work explanation.
> ...for many years there was an assumption that long hours of study indoors, staring closely at books (near work) and never focusing on distant objects, led to myopia. This study belied that error.
> ...increased load of near work was not significantly associated with odds of myopia when factors including parental myopia, demographics, and outdoor activities were adjusted for.
> ...for many years there was an assumption that long hours of study indoors, staring closely at books (near work) and never focusing on distant objects, led to myopia. This study belied that error.
http://sunlightinstitute.org/research-shows-sun-exposure-red...
> ...increased load of near work was not significantly associated with odds of myopia when factors including parental myopia, demographics, and outdoor activities were adjusted for.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3930282/