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Comment by citruscomputing | Hacker News Reader

This is a fascinating article. We know that we need to get kids outside more, but aren't able to prioritize that (except in Taiwan). Instead we're trying to find ways that let us keep using classrooms and screens the same way. I'm very interested in the increased indoor light therapy (for my own use). I would really like for it to be as bright indoors as it is outdoors, matching the spectrum of the sun, without being horrifically expensive.

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Is it now known that light is the primary mechanism?

It's crazy that we still don't know for certain. Being outdoors also often means just looking at things that are further away as well as more eye movement.

Yeah, IIRC, it was in Taiwan or maybe Singapore that they started to see a reverse in the myopia trend in nothing less than one year after having mandated full days outside in school.

But that doesn't have to be the light. That could be having to focus on further away objects.

Probably both equally and correlated.

Myopia gets worse in poor lighting conditions.

Look at those poor moles. :o)

I spent the majority of my life outdoors until my mid 20’s and have quite bad myopia. So perhaps helpful at a population level, but not a magic fix for everyone.

That’s effectively what the documentary I saw concluded (it was a French documentary).

There is a big part of genetics to start with but the impact of the environment is so big that it can make the difference between no correction needed at all up until unmanageable myopia.

Of course you can have a genetic baseline that makes you even more at risk and sensitive but it seems that’s pretty rare overall.

Also I’m curious of what you call quite bad myopia. As an example, my myopia is currently around -7 or -8 and to my surprise, I’m the only one being myopic in my whole family tree. Even my son have a perfect vision.

And it’s true that when I was young, I wasn’t frequently outside and even more rarely in wide open areas.

quite bad might be an exaggeration. Im now at -7.00 in both. I more meant bad in that it’s not something that’s going to be corrected or reversed to any meaningful extent beyond corrective lenses.

In my case though I have glasses, as does my mum, grandmother and both aunts. Clearly a genetic lottery winning family.

A few years ago I heard about a method of using bundles of fiberoptic cable to "pipe" sunlight from a rooftop into rooms. My impression is that it's cheap as hell but impractical.

I can't find the article, but this seems to refer to the same idea: https://www.quora.com/Can-fiber-optic-cables-be-used-to-carr...

You can buy "skylights" that are essentially internally mirrored tubes that accomplish essentially the same thing. I don't believe they're super cheap right now, but I imagine they could be if they became more widely used.

I know someone who installed one in their bathroom and have been surprised at how well it works.

As a building science scholar, I do not recommend skylights or solar tunnels, as they increase the likelihood of roof leaks in the future (as any roof penetration does). Also impairs thermal management due to lack of insulation between the conditioned space and the exterior.

I installed a Velux skylight on one of my previous remodels (replacing an existing low quality skylight), and I still regret it versus decking over the void and deleting the tunnel.

I'm currently renting. But i just want to add that the skylight in my house is the single best thing about it. I'm in a location which is pretty well shaded on all sides of my house. The windows that i do have are relatively small and do not let in all that much light. My house is permanently dim, great for sleeping, terrible for starting work in the morning.

In this scenario, the skylight in my bathroom while i do the morning ready is a godsend. Are there other better solutions? I'm sure there are, but is the prevalence of issues with properly installing skylights much larger than the prevalence of issues with windows?

Would a faux skylight led panel serve this purpose? Windows occasionally must withstand driving rain, a roof must withstand falling rain (on whatever cadence your climate dictates, Florida vs California are wildly different environments for example). Broad strokes, water is the enemy and you’re attempting to avoid intrusion whenever possible.

This is a rabbit hole :)

In short, no, unless you have tens-of-thousands[1][2] to spend on this panel. Rays of sunlight are parallel, an effect that very difficult to emulate.

There are folks who have developed DIY versions, with impressive results[3], but in that case you're trading off way more effort, potentially requiring maintenance, and a lot more space required.

[1]: https://www.coelux.com/en/home-page/index [2]: https://hometronics.com/about-us/press/item/coelux-the-40000... [3]: https://www.youtube.com/watch?v=6bqBsHSwPgw

I’m talking a $100 LED panel from Home Depot, not a full replacement to create a virtual skylight. Is it the appearance of sky or just the light? The light is easy, seeing sky (real or virtual) is hard.

Example: https://www.homedepot.com/p/JONATHAN-Y-2-ft-x-4-ft-Skylight-...

I'm aware of those--I have one, except mine is 5x brighter. It's just not the same.

It doesn't cast the gorgeous shadows sunlight does. It creates glare that makes having the panel surface directly visible, no matter how obtuse the angle, unacceptable.

Sunlight's parallel rays make it so that it's not your window that's bright, it's the things that your window shines light on that are lit up. You can look at your window or the sky all day without any discomfort. And that's just not the case for traditional light panels.

I’ve got a skylight that I hate (faces southwest so in the high summer sun it turns into a heat ray of death) and was planning to have removed, decked over and shingled. Since you are a building science scholar, I am wondering if the tunnel actually needs to be deleted or if I could just put some rigid insulation board at the bottom of the tunnel and then drywall over it?

No need to remove the tunnel if you prefer not to. Rigid foam to a depth that meets the R value for your zone and AHJ requirements (“local code”). Check if any inspection is required before drywalling over the rigid foam.

Thank you

Happy to help, enjoy the project!

Yes, I encountered one for the first time in the bathroom of a holiday let and, having no idea what it was, got very confused as to how I was supposed to turn it off. Fortunately we had an experimental nuclear physicist in the party who was able to explain that turning the light off would actually be a very bad idea.

If we just turned it off for an hour each night, we could solve global warming.

https://en.wikipedia.org/wiki/Light_tube

Mirrors

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