From the Lancet:
Myopia (nearsightedness) has emerged as a major health issue in east Asia, because of:
- increasingly high prevalence in the past few decades. It now affacts 80-90% in school-leavers.
- sight-threatening pathologies associated with high myopia, which now affect 10-20% of those completing secondary schooling in east Asia.
Similar, but less marked, changes are occurring in other parts of the world.
The higher prevalence of myopia in east Asian cities seems to be associated with increasing educational pressures, combined with life-style changes, which have reduced the time children spend outside.
There are no reported major genes for school myopia, although there are several genes associated with high myopia. Any genetic contribution to ethnic differences may be small.
There are some optical and pharmacological interventions that seem promising for preventing the development of myopia or slowing its progression, but the evidence is still preliminary.
Myopia. Prof Ian G Morgan PhD a b , Prof Kyoko Ohno-Matsui MD c, Prof Seang-Mei Saw PhD. The Lancet, Volume 379, Issue 9827, Pages 1739 - 1748, 5 May 2012.
Nearsighted kids may get worse in winter http://trib.in/VcvmC1 -- Myopia progression seem to decrease in periods with longer days and to increase in periods with shorter days. Children should be encouraged to spend more time outside during daytime to prevent myopia (study) http://buff.ly/X1cFSm
Image source: OpenClipArt.org