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I've read this study a while ago, and I think it helped me correct my son's myopia.

When my 5yo kid's eye check came back with "he'll need glasses next year", we started strict "hour+ outside play daily" policy. At his next checkup, he had normal vision. Dr was surprised.

I believe that's still under active research. If this is a factor, my money is more on "your eyes will be focusing more at infinity" rather then low light levels.

https://www.nature.com/news/the-myopia-boom-1.17120

> In the early 2000s, when researchers started to look at specific behaviours, such as books read per week or hours spent reading or using a computer, none seemed to be a major contributor to myopia risk

> Rose's team tried to eliminate any other explanations for this link — for example, that children outdoors were engaged in more physical activity and that this was having the beneficial effect. But time engaged in indoor sports had no such protective association; and time outdoors did, whether children had played sports, attended picnics or simply read on the beach ... what seemed to matter most was the eye's exposure to bright light.

if your child loves watching tv, bring the ipad to the park and make her watch it outside.

> if your child loves watching tv, bring the ipad to the park and make her watch it outside.

I was in agreement until this.

Doesn't this defeat the purpose of being outside? To actually use their eyes to see things near and far, run about and get those muscles working? I don't know what it is about modern parenting that seems wholeheartedly dedicated to the task of making children worship at the altar of Disney and Youtube while denying any chance of developing mental and physical toughness.

The whole point of the comment is that time outside matters more than what is done outside. I don't know the degree to which this is true but if you're going to watch something anyway, doing it outside instead of inside seems like not a bad plan. I don't think they intended anything by specifying tv and you could replace it with reading, board games, drawing, any activity commonly done inside.

Okay if that's the case wouldn't you see similar result if kids watch at a sunny window. Light wise that's pretty similar.

Glass absorbs a huge chunk of the spectrum, both UV and visible. Without studying the actual difference, it is risky to assume that the effect would be similar.

Focusing on infinity more has been tested using glasses designed to force this, it was a popular theory for 60 years or so, and many opticians prescribed glasses which forced people to do this as a result. I cant find it atm, but the result according to a large metastudy was that it caused headaches, and nothing else of note.

Wow in what country do you live in? I have NEVER in my live even have an optician hint at that. The best I got so far was slow understanding of why I am ordering glasses to focus the screen at infinity (one out of 10). All others stare blankly at me and say like "Uh that's illegal, we can give out glasses that potentially ruin your eyes". Well I kept thinking, "Yeah, that's just what you are doing all day" :D

Sweden, Third optician I had did it did it and explained "why", including pointing that the last one also did it according to their logs. Both over adjusting by 0.75, explaining why the first year with each pair gave me a headache. I looked into the causes of nearsightedness afterwards, including the focus nearby/read too much myth, as well I definitely read enough. So was prepared to stop the next optician. But she just called the earlier ones idiots when I mentioned it. Terminal glasses worked well for me.

I just bought weaker glasses online. There you can choose any values

I don't know which it is or if multiple other factors are involved, but if you look at the structure of an eye, there are tissues which compose the iris which are connected to the adjacent tissue of where the lens is nestled. It's quite possible to me that increased use of the iris outdoors to close down and reduce light entering the eye could affect the "dynamic range" of the lens response to focal inputs - especially during the growth stages of kids.

This, and I thus believe that a very bright VR pair of glasses that allows your eyes to focus on infinity would be superior to a monitor.

Could be lack of Vitamin D.

Then you would expect darker regions of the world which have lower serum levels of vitamin D to have more sight problems, I don’t think that’s the case.

I’d actually look at the vision of people with dark skin who now reside in northern latitudes. Typically that is the most vitamin D deficient population, since their melanin levels are tuned for more intense sunlight than their current location provides.

People who have the hobby of photography, might have some intuitive understanding of this brightness difference. If you are shooting with fixed aperture and ISO, your exposure times could easily go from 1/60 indoors to 1/3000 outdoors which is not quite a 100X difference, but close.

This is true, it wasn't until I started photography that I realized how much darker it was inside compared to outside.

In a similar vein an apartment with a few small windows and one with floor to ceiling on two sides - dramatic difference

It's my job and I still get surprised in the evening at how much the exposure changes when it seems static to my eyes.

Not just the difference between indoor and outdoor light, but also the incredible variations between a sunny day in the summer and a cloudy day in winter. There's a pretty incredible difference.

Light perception is logarithmic, not linear, which is why your guess is so far off.

7 'shades' brighter and you're already hitting '100x'.

As are most human senses! Definitely hearing, vision, and smell; possibly also perception of force and weight, though the evidence is conflicting there.

Weight perception is very weird. The size of the object influences how heavy it feels. https://en.wikipedia.org/wiki/Size%E2%80%93weight_illusion

An anecdote for this: I got a heavy carbon steel pan for Christmas that I wished for. I didn’t expect it to be in the big box I got because it seemed to be too lightweight.

Don't forget sound perception, which is one big reason we measure loudness in decibels.

I said "hearing" :-P

It is not actually "logarithmic" per se.

At a given level of adaptation the relation between luminance and perceived lightness is closer to a square root.

But over the course of about 30 minutes there are several different kinds of adaptations (some faster than that) which the eye/brain can make to the current light level, which has an effect of shifting that curve up or down by up to several orders of magnitude.

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

I used to live almost on the equator. Before adolescence, I would spent most of my time outdoors. Very stable weather so windows were open most of the day (and night). There was often direct sunlight even indoors. We would go to the beach every weekend. I ended up with -5.00 and -5.25

Maybe this would decrease the prevalence, if you are looking at the entire population. But it's not like you, as an individual, will be immune if you just stay outside.

I live in the dark North and have always been fond of screens. Being outdoorsy is a much later-acquired taste. My vision at soon 30 is still 20/20.

Probability is a strange beast.

That's only correlation, light brightness has nothing to do with myopia. It's more likely from looking at things farther away from the face outside so that there is less light focused on the fovea.

"light brightness has nothing to do with myopia" - that's a big claim and will need some evidence to back it up, especially given the many studies that suggest otherwise.

This is still a topic with many unknowns, but we have to follow the evidence as much as we can. Evidence should always beat data-free guesses.

See my other replies. I also feel worried reading this, because it doesn't look like you've researched the subject, and I always worry about lack of understanding of myopia progression with people just talking about a subject they aren't familiar with.

kind of, kind of not. To the extent that brightness contracts your pupil, and the depth of field available to your eye increases with smaller pupil size[1]. People with focus issues find they can always focus when the light is bright enough (assuming normally functioning pupils).

So there are optical properties that are affected by bright light, and your eyes respond to that. What the mechanism is for affecting overall focus range of your eye? I would agree that is unstated/unknown.

[1] Which, as a science project, is fun to demonstrate that a pin hole camera doesn't need a lens for this reason.

Please do research on myopia progression. It's not unknown. This entire thread is full of people guessing at things they don't have any experience in.

A brief look at citations on Wikipedia seems to contradict everything you've said. Maybe you'd like to link some research?

Your reply is a good example. I haven't seen anyone in this HN post's comments talk about how myopia works. I legitimately do not understand why so few people know even the basics of myopia progression. All of these comments are, pun intended, the blind leading the blind. I especially don't understand it given how common myopia is and how important it is for parents to understand it for their children.

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1. Glasses that blur what's on peripheral vision https://abc11.com/amp/4176773/

> too much time spent in front of a screen confuses the eye, since everything is in focus. The eye keeps growing, leading to myopia.

2. Glasses to stop myopia are successful in multi-site trial https://newsroom.uw.edu/news/glasses-stop-myopia-are-success...

Glasses with fogged edges prevent over focus:

> What’s supposed to happen as your eye grows, is that things should begin to go out of focus in the periphery of your vision. That’s a signal for the eyes to stop growing.

3. Multifocal contact lenses slow myopia progression in children https://www.nih.gov/news-events/nih-research-matters/multifo...

> Animal studies have shown that focusing light in front of the retina cues the eye to slow growth.

4. Putting contact lenses on monkeys _causes_ myopia and removing them slows myopia growth https://www.nature.com/articles/s41598-019-48009-3

5. "How Atropine Eye Drops Can Slow Myopia Progression" https://www.myopiainstitute.com/eye-care/how-atropine-eye-dr...

> Applying atropine eye drops dilates the pupils and temporarily paralyzes the focusing muscle inside the eye. It also relaxes the eyes’ focusing mechanisms.

Your eye grows without your brain's involvement. Sharp focus on the back of the eye, especially in the periphery, tells the eye to grow longer because it's overfocusing. This leads to the worsening of myopia. Things that cause sharp focus on the retina and fovea: contacts, glasses, and holding things close to your face that keep everything in focus. This may be why being outside is correlated with slowing myopia progression, because you wont have things constantly in focus in your peripheral vision from it being close to you.

I have a serious question: did you not come across any of this research? No one seems to have familiarity with these concepts in this HN thread. Did you see articles like these and skip over them? Or, maybe, were you only googling for myopia and sunlight, which is unlikely to return results like these?

There is also a lot more research, see: http://www.myopia-manual.de/private/manual-2021-jan.pdf

>The development of chicks towards emmetropization was observed at various levels of illumination: (10.000 Lux, 500 Lux and 50 Lux). Result: After 90 days 50 Lux resulted in a mean myopia of –2.41 D, 500 Lux resulted in +0.03 D, and 10.000 Lux resulted in hyperopia of +1.1 D.

>"Categorized according to their objectively measured average daily light exposure and adjusting for potential confounders (age, sex, baseline axial length, parental myopia, nearwork, and physical activity), children experiencing low average daily light exposure (mean daily light exposure: 459 ± 117 lux, annual eye growth: 0.13 mm/y) exhibited significantly greater eye growth than children experiencing moderate (842 ± 109 lux, 0.060 mm/y), and high (1455 ± 317 lux, 0.065 mm/y) average daily light exposure levels."

>for myopic children 6 to 12 years old a mean progression of – 0.35 D in winter and –0.14 D in summer. This was attributed to the children's extended time spent outdoors in summer

Getting more sunlight is the most helpful thing one can do without special equipment

Thank you, this is interesting!

>I have a serious question: did you not come across any of this research?

I hadn't seen the more recent developments on these preventative glasses, no. However I don't tend to give too much credence to individual studies especially when reported through mainstream media. You see such studies and articles supporting all kinds of contradictory conclusions all the time.

Wikipedia isn't a reliable source, but it is kind of useful as a quick overview of current ideas on a topic. Skimming the article,

>The near work hypothesis, also referred to as the "use-abuse theory" states that spending time involved in near work strains the intraocular and extraocular muscles. Some studies support the hypothesis, while other studies do not.[3] While an association is present, it is not clearly causal.[3]

and

>There is preliminary evidence that the protective effect of outdoor activities on the development of myopia is due, at least in part, to the effect of long hours of exposure to daylight on the production and the release of retinal dopamine.[15][29][30][31]

So, immediately it seems like we aren't so certain as you suggest we are what the cause of myopia is. And your assertion that "..exposure to light brightness has nothing to do with myopia" is directly contradicted here. And from a cited recent (2019) review paper [1]

> Huang et al. highlighted, in a recent systematic review and meta-analysis, that near-work activities were related with higher odds of myopia (odds ratio 1.14; 95% CI 1.08–1.20) and that the odds of myopia increased by 2% (OR: 1.02; 95% CI 1.01–1.03) for every one diopter-hour more of weekly near work [110].

> In contrast, there are studies reporting that near work is not associated with faster rates of myopia progression [85, 111–113].

> Therefore the relationship between near work and myopia is complex and needs to be investigated.

> On the other hand, several recent epidemiological studies suggest that greater time spent outdoors might have a protective effect against myopia development and progression [114–116].

So, though I am far from being an expert after reading these few articles, they all seem to strongly contradict your assertion that "It's not unknown", and also that the research all agrees with your points.

[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6875023/

> The near work hypothesis, also referred to as the "use-abuse theory" states that spending time involved in near work strains the intraocular and extraocular muscles.

Goodness Wikipedia, this isn't the theory at all. It has nothing to do with muscle strain. We know for a fact that in youth, the eyeball grows longer when it's overfocusing (especially in fovea), and stops growing when things are blurry. That's how it maintain focus as you grow and age. This isn't a theory, it's how the eye works. There are already multiple types of technology that successfully slow and stop myopia based on this principle, as listed in my post.

The mechanism of outdoor light is just a hypothesis without known direct link. It may be related but there's no direct evidence for it yet.

Correlation does not imply causation but it does imply having something to do with the other. Your first sentence contradicts itself.

> Correlation does not imply causation but it does imply having something to do with the other

Correlation does not imply having something to do with another.

For example, in the first decade of the 21st century, spending on space exploration had a 99.8% correlation with a specific subset of suicides (hanging?).

"Correlation does not imply having something to do with another."

By its very definition, "correlation" means exactly "a mutual relation": https://www.dictionary.com/browse/correlation The example you're giving is called coincidence not correlation. There are times where words' etymologies loose their connection with their current meaning, but that is not the case here, where we have "con" meaning "together" + "relation", which is a logical construction agreeing with word's meaning.

In the context of scientific research on myopia, we're pretty clearly talking about definition #3, not definition #1:

> Statistics. the degree to which two or more attributes or measurements on the same group of elements show a tendency to vary together.

It depends on what you mean by "having something to do with the other" but I see what you mean. I should've assumed the more favorable interpretation of the comment I was replying to. Reminds me of the pirates and global warming correlation.

You can only see that far away if the light energy is that abundant.

That's a pretty low amount of light, though. The sun doesn't even have to be above the horizon - Twilight, in different darknesses, exists. And you'll still be looking at things a bit further and the light isn't as concentrated.

The amount of detail sometimes varies, but then again, fog will do that especially when it is bright.

When I tried to inject fake daylight into my basement office, I realised just how "special" daylight is. It comes in from everywhere. Flood fills with so much light as such a broad spectrum.

You might be interested in this video too. There’s more to it than just the color, sunlight’s rays are (virtually) parallel, because the light source is so far away. https://youtu.be/6bqBsHSwPgw

Regarding the spectrum, you might be interested in these https://store.waveformlighting.com/collections/led-strips/pr...

When last I looked, there were some very expensively priced daylight lights - complete with blue sky. CoeLux has a scattered light indoor skylight.

I always thought my myopia was caused by computer usage. Reading this it sounds more likely that it was growing up in Calgary, Canada and spending huge amounts of time indoors and in basements.

Well it is, because the more you are on your computer, the less you are outside.

Please see my other replies in this thread. Why are you both guessing at this?

It's not possible to know what caused my myopia - all I can do is guess based on the current evidence around the subject. Which is not as conclusive as you seem to think - the jury is still out on this subject.

I made an appointment with a local dermatologist about some sunburn that never seems to heal up. He's a young German guy living here in New Zealand. After a quick examination: "So! You have solar keratosis! How long have you been wearing the hat?" Me: "Oh 5 years or so". Him: "And how long have you lived here?" Me: "All my life, 60 years". Him: "Just so! It seems all Kiwis have solar keratosis ja?".

In other words, there are downsides to being outside in that 1000 times (maybe 10000 times here) brightness. The really annoying thing is that my eyes were buggered from a young age too, despite all that brightness.

> 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."

So, it's not even an individual correlation but a population-frequency-correlation between populations in different physical environments, which is so even more likely than an individual correlation to represent an effect other than causation in either direction, such as any other environmental (or population-genetic-distribution) difference.

Just as a side note, its not that people are terrible at perceiving brightness, it's just that brightness perception (like loudness) is logarithmic. So if a person says it is 2x brighter outside, and a linear measurement instrument says it is 100x brighter, that is in fact roughly consistent.

I’d wager there’s an effect like this for adults too. I didn’t need glasses until I got my first office job.

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

The study was done in Singapore and Malaysia. It looks like an interesting study to do in different regions of the world. e.g Western Europe where it is notably cloudier than Singapore.

I noticed that when I started to measure the lightning in a room for home automation purposes.

It is really, really difficult to find the right spot that reflects "the light in the room" and then to find a threshold to switch on the lights "at the moment I would have done that".

I constantly hesitate between 30 and 100 lx, it is so dependent on the subjective light outside.

I remember reading a post on here about someone's home office lighting setup which had some insane number of lumens and was equivalent to being outdoors at dusk. That's when I became aware of the huge difference in illumination.

Any chance you saved/upvoted that post? I can’t find it but would love to read it.

Possibly this one: https://news.ycombinator.com/item?id=24984862

Thanks

Before you change your internal mental calibration, this of course changes based on latitude and time. The difference between daylight and a cloudy day midwinter in Northern Europe is probably not going to be 100x.