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Comment by gaspoweredcat | Hacker News Reader

is there actually any solid evidence that screen time causes myopia? my entire family wear glasses with the sole exception of me and i spend drastically more time in front of screens than they do

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A side effect of spending many hours inside staring at a screen is that you are typically not exposed as much to outside brightness levels. The level of light that your eyes receive has a drastic impact on the way that your eye develops and not getting enough leads to myopia because the different parts of the eye end up growing at different rates.

Of course, when your eyes have fully developed you want to avoid the bright light to prevent cataracts. It's hard to win in biology.

The belief* I had was that it is actually long periods of focus at a restricted set of ranges, eg some kind of atrophy. Though as in the footnote I realize this could be absorbed nonsense that followed the standard “screens == poor vision”. Happily when I was a child the threat to vision was reading books, which modern children are no longer at risk of ;)

* when I went to write this reply I realized that I don’t recall actually reading a paper on it, so it’s quite possible that it’s just another “everyone knows”-type fallacy

As far as I've read about it, correlations have been found, but not pointing to any single primary cause. For example, it might be that if you have N out of M unfavorable gene-environment interactions, the development of your vision suffers enough to be considered myopic.

Not in the sense that the screen, or any near work is the primary cause. Except for genetic factors it seems more related to the exposure to light of a brightness which can usually only be found outdoors.

Obviously this can correlate with both screen time, reading, and washing the dishes.

It's not really about myopia as such... There's really two things going on here: (1) Many people increasingly regard video games as an addictive drug [1]. And there's plenty of anecdotal evidence of young men literally dying because they don't do anything else but play video games for 10+ hours a day, everyday. For various reasons, Chinese culture takes a very, very dim perspective of addictive drugs. (2) Some people believe Tencent is too powerful. It's well on its way to being China's first trillion dollar company and it's not just a Chinese company any more, it's a multinational corporation (MNC). For various reasons, Chinese culture takes a very dim perspective of MNCs [3].

I suspect pragmatism will win in the end though. There's enormous demand for video games and it's simply not practical to completely ban them a la actual chemical drugs. To do so would also be ceding what is likely a trillion dollar market to South Korea... which would be totally insane.

[1] https://index.qz.com/1024281/honor-of-kings-called-a-drug-in...

[2] http://www.ejinsight.com/20180608-tencent-walking-a-fine-lin...

[3] https://www.brookings.edu/articles/are-chinas-multinational-...

It's genetic - some eyes grow incorrectly and the lens doesn't focus on the retina. It runs in my family, and I'll bet it runs in many Chinese families.

I had LASIK 13 years ago and haven't looked back. Will we see a wave of LASIK surgery in Chinese communities in the near future?

https://bjo.bmj.com/content/85/5/521

I don't see how that link answers the above question, care to elaborate ?

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