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The weak expert consensus is now that the largest contributor to near-sightedness is reduced exposure to sunlight as a young child which causes the eyes to grow

The weak expert consensus is now that the largest contributor to near-sightedness is reduced exposure to sunlight as a young child which causes the eyes to grow slightly differently. Do places above the Arctic circle have higher rates of near-sightedness? EDIT: apparently there is a correlation, but it seems to me it's not as strong as the sunlight theory would have suggested. http://onlinelibrary.wiley.com/doi/10.1046/j.1395-3907.2003.0151.x/full http://onlinelibrary.wiley.com/doi/10.1046/j.1395-3907.2003....

taneq 9y ago
I can't understand how sunlight exposure could be more of a problem than excessive close-range work (reading books, etc.) during formative years.
- Filligree 9y ago
  Biology doesn't have to make sense, and a lot of it doesn't. There are weirder correlations in there.
- NiklasMort 9y ago
  That is a misconception and has been debunked (same goes for reading in dim light), I been a kid like that and I basically spend all day since the last 15y in front of a computer and I have near perfect eye sight. The "screen time" is not at fault per se if you get enough outside time. The reason is not just any "sunlight exposure" but it is about UV radiation that is important for the development of the eye.
  - leereeves 9y ago
    The linked study doesn't agree that "that is a misconception and has been debunked". It says it's true: > As indicated by other reports, myopia was found to be associated with ... education and nearwork.
    - jessriedel 9y ago
      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. http://sunlightinstitute.org/research-shows-sun-exposure-reduces-myopia/ 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/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3930282/
    - NiklasMort 9y ago
      wrong conclusion...it is because those people are not doing this outside ;) so yes if you sit all day at home and read books it won't be good but the reason is not the reading distance. I remember as a kid my parents always said "don't sit so close to the TV"...same story there
nwatson 9y ago
Perhaps there's correlation between sunlight exposure and being out in "large spaces" where the majority of what you're seeing is farther away than your homes' walls. Having developing eyes focus on a mountain panorama or distant trees across a lake leads to different stresses on the eyeball ... or perhaps some different training for physiological systems that deal with focus.
- jessriedel 9y ago
  > Perhaps there's correlation between sunlight exposure and being out in "large spaces" where the majority of what you're seeing is farther away than your homes' walls. This was one of the other leading hypotheses for a long time. More recent data came down pretty decidedly on UV light rather than focal range. See my other comment: https://news.ycombinator.com/item?id=16248851 https://news.ycombinator.com/item?id=16248851
e12e 9y ago
Just a note, that with polar night comes a) long winter with sun and snow, and b) polar day.
- e12e 9y ago
  Further, polar night in Tromsø ends around 21st of January, while the midnight sun starts around 21st of May - that's roughly 17 weeks going from the sun not rising, to the sun not setting - more than an hour of difference, week to week on average (0-24 hours, in 17 weeks). [ed: of course, the change isn't linear: https://www.timeanddate.com/sun/norway/tromso https://www.timeanddate.com/sun/norway/tromso ]

taneq 9y ago

I can't understand how sunlight exposure could be more of a problem than excessive close-range work (reading books, etc.) during formative years.

Filligree 9y ago
Biology doesn't have to make sense, and a lot of it doesn't. There are weirder correlations in there.
NiklasMort 9y ago
That is a misconception and has been debunked (same goes for reading in dim light), I been a kid like that and I basically spend all day since the last 15y in front of a computer and I have near perfect eye sight. The "screen time" is not at fault per se if you get enough outside time. The reason is not just any "sunlight exposure" but it is about UV radiation that is important for the development of the eye.
- leereeves 9y ago
  The linked study doesn't agree that "that is a misconception and has been debunked". It says it's true: > As indicated by other reports, myopia was found to be associated with ... education and nearwork.
  - jessriedel 9y ago
    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. http://sunlightinstitute.org/research-shows-sun-exposure-reduces-myopia/ 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/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3930282/
  - NiklasMort 9y ago
    wrong conclusion...it is because those people are not doing this outside ;) so yes if you sit all day at home and read books it won't be good but the reason is not the reading distance. I remember as a kid my parents always said "don't sit so close to the TV"...same story there

nwatson 9y ago

Perhaps there's correlation between sunlight exposure and being out in "large spaces" where the majority of what you're seeing is farther away than your homes' walls. Having developing eyes focus on a mountain panorama or distant trees across a lake leads to different stresses on the eyeball ... or perhaps some different training for physiological systems that deal with focus.

jessriedel 9y ago
> Perhaps there's correlation between sunlight exposure and being out in "large spaces" where the majority of what you're seeing is farther away than your homes' walls. This was one of the other leading hypotheses for a long time. More recent data came down pretty decidedly on UV light rather than focal range. See my other comment: https://news.ycombinator.com/item?id=16248851 https://news.ycombinator.com/item?id=16248851

e12e 9y ago

Just a note, that with polar night comes a) long winter with sun and snow, and b) polar day.

e12e 9y ago
Further, polar night in Tromsø ends around 21st of January, while the midnight sun starts around 21st of May - that's roughly 17 weeks going from the sun not rising, to the sun not setting - more than an hour of difference, week to week on average (0-24 hours, in 17 weeks). [ed: of course, the change isn't linear: https://www.timeanddate.com/sun/norway/tromso https://www.timeanddate.com/sun/norway/tromso ]