[mattjaynes]

Ask yourself, how much brighter is it outside than inside (assuming a sunny day vs a brightly lit office)? Before looking into this, I would have guessed 2X or 3X, but would you believe it's actually over 100X!

I bet most people's guess would also be off by 1 or 2 orders of magnitude.

Even outdoors in the shade, it is over 50X brighter than indoors.

(For specific numbers and comparisons, see: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6656201/ )

Apparently, our eyes adjust so quickly to the difference that we have a very poor sense of the magnitude of light change between indoors and outdoors.

I bring this up because one of the largest factors in myopia development appears to be outdoor light exposure in childhood.

Genetics are likely a factor too, but light exposure seems to have a huge effect: "The prevalence of myopia in 6- and 7-year-old children of Chinese ethnicity was significantly lower in Sydney (3.3%) than in Singapore (29.1%), while patterns of daily outdoor light exposure showed that children living in Singapore were exposed to significantly less daily outdoor light than Australian children." (from the same study linked above)

The obvious takeaway for parents, schools, and governments: ensure your children have plenty of outdoor playtime. It will greatly reduce instances of myopia (not to mention the benefits from higher Vitamin D levels, exercise, etc).

(This is a repost of my comment from 3 years ago on the same topic: https://news.ycombinator.com/item?id=25909557 )

[thriftwy]

So if you're living in a multi-storey apartment block in a place where there are periods of rain, cold and darkness, naturally your routine will not be conductive of spending lots of time outdoors. What's the plan B?

Sure, if you live in Australia with a tiny population living in own houses (while they can still afford those), they risk UV-burns more than myopia. But that doesn't scale that great.

[walterbell]

Nothing can replace full spectrum natural light, so face a window or go outside, when possible, https://endmyopia.org/why-vision-is-worse-at-night-and-on-cl...

Indoor, try Sylvania TruWave LED (2700K, high CRI, low flicker, high lumens), https://gembared.com/blogs/musings/the-best-daytime-white-li...

[joenot443]

I think most people are capable of spending time outside every day, even if they live in an apartment.

I’m typing this from a cafe in Manhattan, I try to walk at least a few km every morning. I did the same thing when I lived in Seattle. My understanding is you don’t need direct Australia-level sun to get the benefits we’re talking about.

[scotty79]

Maybe have your kids room as bright as outside with >200W of LED lightning?