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Shortsightedness has become an epidemic

528 points| nilsbunger | 3 years ago |economist.com | reply

400 comments

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[+] tominous|3 years ago|reply
Almost all children are born hypermetropic (far-sighted). The growth of the eyeball is calibrated by the amount of defocus (blur) experienced. More defocus, more growth, which reduces hypermetropia.

My hypothesis is that less sunlight means wider pupils and more defocus (contrast to a pinhole camera), so more eye growth.

Even with perfect eyesight, there's a 2-diopter difference between focussing blue light and red light due to chromatic aberration. Only narrow pupils can reduce this blur in white light.

I'm also curious whether older TVs with big blurry pixels (or low res images upscaled and smeared onto newer screens) trigger the same mechanism. These days I certainly feel physically uncomfortable looking at media like that, like my eyes aren't focussing quite right.

The other problem is that once eyes have grown too long and are myopic (near-sighted) they experience even more defocus and grow more. See for example [1] which discusses how under-correction of myopia accelerates progression.

[1] https://reviewofmm.com/does-the-undercorrection-of-myopia-in...

[+] kenbolton|3 years ago|reply
I wore glasses for a few years in high school because I had trouble seeing the blackboard from anywhere but the front row. I started hiking and kayaking every day, especially in places where I could see for many miles. I also migrated from CRT to LCD to LED screens, and more recently to e-ink devices when possible. Very fine print in a dark space is hard to read, but I can read a moving US license plate from six blocks away. Yesterday I recognized a friend a mile and a half away by their paddle-stroke. I am able to differentiate a bald eagle from an osprey at two miles based on the shape of the wings, and see a fish in talons at about a mile. (Friday I observed an osprey dive, catch a fish, head towards the nest, then get chased for thirty minutes by a bald eagle. Nasty, opportunistic birds, bald eagles. I get why Benjamin Franklin held them in such contempt. I lost the pair when they went behind a mountain about three miles away.) In speaking with ophthalmologists, there is wide support for my hypothesis that the near-daily outdoor activity and frequent change of focal distance–from a nautical chart on my foredeck to the bow wave of a tanker eight miles out–has preserved and likely improved my vision. The data: 20/20 in primary school, 20/23 in high school, 20/20 during my higher education, and 20/13 and improving as I approach retirement. A fun trick is to describe an approaching vessel before others have seen it.
[+] mbrameld|3 years ago|reply

    I am able to differentiate a bald eagle from an osprey at two miles based on the shape of the wings
I wonder how you judge the distances? I'm a helicopter pilot and I don't even bother looking for traffic farther than 2 miles out unless it's an airliner. I have radar telling me how far away they are so I know the distances are accurate.
[+] amelius|3 years ago|reply
This makes me wonder: is there a lens that you could use instead of glasses that will make your computer screen appear as if it is further away? Could it help people regain their far-sight?
[+] Elora|3 years ago|reply
> I also migrated from CRT to LCD to LED screens, and more recently to e-ink devices when possible.

I too use eInk whenever possible but that's just for reading (a passion of mine). All current computer monitors are LED AFAIK, is there any research tho that it's better for sight, or are you simply stating that you migrated as the technology changed?

I'm thinking that OLEDs are the best looking but one of their weaknesses often mentioned is that they aren't as bright; if you have lots of light (ideally natural sunlight) they may prove to be counterproductive if you have to strain to see due to appearing dim.

[+] shadowtree|3 years ago|reply
You're getting far-sighted as you're getting older.
[+] abledon|3 years ago|reply
do you work a regular programming 9-5 job infront of a screen...?

there is the Dasung E-ink 23" monitor

[+] underwater|3 years ago|reply
My child is following in my footsteps and has been prescribed glasses for nearsightedness. Her optometrist told us she should be watching TV rather than reading books. This was both surprising and upsetting, especially since she loves reading.

This lead me on an interesting deep dive into existing research. What surprised me were the massive gaps in understanding. Scientist have at best established correlation between close up work and nearsightedness, and a negative correlation with spending time outside. The actual mechanism in play is unknown, for example the theories about sunlight are still untested. The specific types of close up work that cause issues is unknown. Some scientists have proposed that it's the contrast between white pages and black text that actually causes issues with reading.

My conclusion was that anyone who confidently asserts that $x causes nearsightedness is wrong (this thread is a case in point).

[+] Aulig|3 years ago|reply
Honestly, myopia is not complicated (Kepler pretty much had it right in 1604 already). There's countless studies showing that axial length (eyeball length) changes in both directions, where elongation increases myopia. How do you change it? You get defocus (blur) which makes the eye adjust in the direction to reduce the blur.

Practically: use weaker (around 1.5 diopters) or no glasses during close-up work (reading, computer work, smartphones) and your regular or .25D weaker glasses for distance vision. Always use your full strength glasses for driving and safety critical activities.

You can expect around a .75D decrease in myopia per year. Personally, I started with around -5.5D and am now (1.5 years later) at -2.5D.

Obviously I didn't come up with this myself, there's a huge group over at https://endmyopia.org

Don't get put off by the sarcastic tone of the website. Look into the studies regarding axial length, pseudomyopia and lens induced myopia if you'd like. You can find plenty of studies linked as well as the practical steps on endmyopia. Note: You don't have to buy the guy's courses, just read his blog and free email guide.

[+] planarhobbit|3 years ago|reply
Hard to believe after all these years EndMyopia is not only being promoted on HN, but is consistently one of the most upvoted things on the subject. I figured the pros here would slice and dice and find issues with the research and recommendations and explain in depth why it’s snake oil (if it is), but it’s been a fairly forgiving topic.
[+] nealabq|3 years ago|reply
This probably works for most people. But I've used 2-diopter weak glasses for the last 40 years, whenever I'm indoors. I think it helped slow the worsening of progression of my nearsightedness, but didn't stop it and certainly didn't reverse it.
[+] atombender|3 years ago|reply
Is there a single step-by-step guide that shows what to do?

All I can find on that (frankly quite awful) site are ways to sign up to a course by email, lots of podcast episodes, testimonials for people that improved their eyesight, and endless photos of what I assume is the site's creator. The "Guides" page doesn't actually have any guides, just more of the same.

From what I can tell, the guy really wants to sell you a course, but at the same time, they are all "sold out".

[+] alephnan|3 years ago|reply
> Practically: use weaker (around 1.5 diopters)

This is what optometrists in Asia do, except in the West there is always a cultural tendency to "overprescribe"

[+] ymolodtsov|3 years ago|reply
That's outdated advice popular among doctors like 30 years ago. No credible specialist would tell you to wear weaker glasses in 2022.
[+] spiffytech|3 years ago|reply
In my early teens I had 20/15 vision. By the time I went to college I was wearing glasses for nearsightedness.

I'm pretty sure it's because I got interested in computers, and started spending all day staring 3ft ahead instead of glancing around outdoors.

Some friends in my computer science program passed around each other's glasses and found we all had nearly the same prescription. That didn't seem like a coincidence.

[+] rootusrootus|3 years ago|reply
That may just be lucky coincidence. I've been a computer nerd spending way too many hours in front of my computer since I was a teen. Last eye exam I had was a few years back when I turned 45. 20/20 in one eye, but after I made a remark about having been 20/15 when younger, the tech said "let's try!" and I could still do it. Barely. In only one eye now. But still, after all these years.

But really it's presbyopia that's bothered me. I'm glad my distance vision is great, but the loss of close-up focus is massively inconvenient. Reading glasses make me want to throw up within a matter of minutes. Not sure what my long term plan is aside from suffer.

[+] cozzyd|3 years ago|reply
I still have 20/15 vision at 35, despite probably averaging over 8 hours a day staring at computer screens for over 2/3 of my life... But maybe I'd have superhuman vision otherwise?
[+] plonk|3 years ago|reply
I spent 10 hours a day on computers when I wasn't at school during middle school. Started at the end of primary school and continued until now. I pass the letter-reading tests at the GP when I'm not too tired, so I think I have pretty good vision.

Maybe that's because I didn't always have a computer nearby and had to spend time outside too as a kid.

[+] underwater|3 years ago|reply
There are also theories that the cause and effect are actually in the other direction: kids with poor distance vision are more likely to spend time reading and studying rather than be outside playing sports.
[+] _uy6i|3 years ago|reply
Gross generalization, but my suspicion is that it’s not the all day staring at computer (that’s most adults these days) but also many CS types spend their free time in front of a screen as well…
[+] t_von_doom|3 years ago|reply
I wonder how much that might be explained by variance around the mean
[+] 300bps|3 years ago|reply
I got my first computer at 10, was 20/40 vision at 16 and am probably around 20/80 right not.

Honestly I'm glad that I am now that I'm in my 40s. Without glasses or contacts, I can read something right up against my nose. Makes it so much easier to work on electronics and other small items - I just take my glasses off and I see up close perfectly well.

[+] hk1337|3 years ago|reply
The different usage of words and their meanings in English is interesting and makes me think this weird miscommunication is why we have so many arguments. In my everyday, the article would be referring to nearsightedness, short sighted would be when someone doesn’t think through all the possible things, lacking foresight. By definition it’s both but in every day use it’s not.
[+] zymhan|3 years ago|reply
Yeah, given that this is an Economist article, I assumed they meant "lack of foresight", since they often write similar titles
[+] wiether|3 years ago|reply
I'm in the same boat; I was expecting to read an article about managers/CEOs taking short-sighted decisions.

To be noted, I'm French, English is not my native language so when I realized my mistake I thought that was because in the case of this title it was obvious that it is about eyes but I just didn't knew how to catch the clues.

[+] martyvis|3 years ago|reply
In everyday use in this part of the world you never hear the word near-sighted. In Australia and I think a lot of other British English countries, short-sighted is the plain English term for myopic. (But the thing is most of us know that the US uses the other term)
[+] ultra_nick|3 years ago|reply
Homographs are a pain for natural language processing.

Homophones are a pain for us bad spellers.

[+] fillerInk|3 years ago|reply
Not just with light, spending more time indoors means kids don't have to focus their eyes on longer distances these days. There would be a correlation between the amount of time spent indoors during the formative years and the chances of becoming myopic in the future.
[+] sandstrom|3 years ago|reply
For several decades it has been known that myopia (nearsightedness) and intelligence are correlated[1][2]. Initially it was speculated that reading caused nearsightedness, and through that higher intelligence. There is probably some truth to that.

But with modern DNA sequencing techniques researches has found genes that seem to affect both[3][4].

The hypothesis is that one (or a set of) genes affects both eye size growth (myopia is often caused by the eye being "too long") and neocortical size (associated with intelligence).

Although this probably won't surprise anyone in this research field, I recently read about it -- with my non-nearsighted eyes :) -- and found it interesting. So I wanted to share, since it's somewhat related to this topic.

[1] https://jamanetwork.com/journals/jamaophthalmology/article-a...

[2] https://europepmc.org/article/med/2904062

[3] https://www.nature.com/articles/srep45977

[4] https://pubmed.ncbi.nlm.nih.gov/19127804/

[+] stackbutterflow|3 years ago|reply
I noticed my eyesight gets better after many hours outside not looking at any screen. And worsen after many hours in front of a screen. Is there a name for that?
[+] KVFinn|3 years ago|reply
I think it's multiple things.

Your eye is a muscle, focusing only at close range keeps the range of motion tight. Just like your back and neck might get stiff sitting all day.

Sunlight means smaller pupil, wider depth of field, just like a camera.

(My speculation) More light gives you brain more information to clean up or upscale a blurry image. This effect even seems to last when you leave sunlight, for awhile. It's like I fine tuned my neurons to prioritize blur reduction, and it takes awhile for them to fall back into normal processing. If this is true, my guess is that I might be trading off contrast or color details for sharpness.

[+] AndrewDucker|3 years ago|reply
Tiredness of the eye muscles after many hours forcing the focus to a short distance.
[+] rnd420_69|3 years ago|reply
have you verified that it actually gets better and that you're not just getting used to it?

I used to think the same thing when I just tried not wearing glasses for a while. I could swear that it was awful at first but over time my no-glases eyesight improved tremendously. I then did a really simple distance reading test and it was obvious that it didn't improve at all and the effect was imagined.

[+] ymolodtsov|3 years ago|reply
You are getting muscle spasm on top of myopia. Unlike the changing physiology of the eye, this is reversible.
[+] tamrix|3 years ago|reply
My parents would call it square eyes lol
[+] misslibby|3 years ago|reply
Could it just be dryness of the eyes?
[+] d13|3 years ago|reply
Probably because your pupils dilate in bright sunlight, which improves focus?
[+] stakkur|3 years ago|reply
>Sedentary, white-collar jobs are less arduous (and less lethal) than manual work. They also promote obesity and heart disease.

I'm always baffled by the dismissive wave of the "activity level causes obesity and heart disease" trope--because it's mostly wrong. The first world diet is the primary cause of obesity and heart disease, and it's well-proven. Starch and sugar, processed foods, a diet primarily consisting of carbohydrates. Diet is the driver, not activity level.

[+] ClumsyPilot|3 years ago|reply
Seeing this is the economist, I thought they meant shortsightedness of our business and industry leaders. Was a bit dissapointed that instead of much needed self-reflection, the topic is far more pedestrian.
[+] 0dayz|3 years ago|reply
This has me perplexed, if it has to do with sunlight, wouldn't then Nordic countries have a very high level of shortsightedness?
[+] kwhitefoot|3 years ago|reply
Outdoor activities are very common in Norway winter and summer. The skies are often quite clear too.

And, at least where I live, kindergartens have the children playing outside most of the time, summer and winter, rain or shine.

My impression is that short-sightedness is in fact rarer in Norway than in the UK but it's not something I actually have statistics for.

I fear that it might be changing now as so many children, boys in particular, spend so much time using computers.

[+] drited|3 years ago|reply
I'm hopeful that the shift to VR from PC gaming and perhaps also office productivity will help with myopia. Might seem counter-intuitive given the VR lens is next to the eye but focus in VR is in the distance. Even productivity in VR is usually done on huge screens further away from the user than traditions pc screens.
[+] mattlondon|3 years ago|reply
I wonder if indoor lighting at the appropriate temperature would help prevent this?

In the UK we don't get a lot of sunlight in the winter months. It would be nice to know that we can turn on a "sun lamp" or whatever for homework time to help alleviate the issues.

[+] scotty79|3 years ago|reply
Could we just have rooms lit as strongly as outdoors?
[+] kamaal|3 years ago|reply
Pretty sure in the recent times COVID has worsened this. I do exercise often these days. But its nothing like the morning workout, lunch time socialising, and tea time walks with colleagues before COVID.

These days apart from the workout in the morning I get no outdoor activity, its just staring at every decreasing(sizes of) screens. I'm showing early symptoms of Shortsightedness. Several other colleagues tell me the same, there's also additional problem of people getting obese staying at home.

Though schools have opened. Last two years were equally worse for kids, no play, classes on smartphones and laptops.

Humans have not evolved to live like this.

[+] eastbound|3 years ago|reply
Why can we have 2-lense glasses that move the focus to infinity?

ELI5: In opticals, “rays” coming from a near object (=mobile phone) are angled, while rays coming from afar (=end of a landscape) are parallel. The job of pupils is to bend the rays from the focal point ahead to the focal point on the receptors in the eye. The eye is a rest when looking afar, because rays come parallel, and thus there isn’t much to do. The eye is strained when trying to focus one something closer.

I’ve always wondered why we all had that UV filter on screens and never took care of making the rays from the computer screen parallel, using a lense.

[+] mrkramer|3 years ago|reply
I usually don't agree with The Economist but I agree with them on this one, people spend too much time indoor and that's why there is an epidemic of shortsightedness.

I would actually call it pandemic because it is affecting all developed countries because majority of their workforce works indoor and then goes home or to the gym....again indoor environment.

[+] FollowingTheDao|3 years ago|reply
Is dopamine playing a role? Like social media use on top of less sunlight? Some of the genetics linked to myopia involve dopamine:

https://www.revieweducationgroup.com/ce/how-environment-and-...

"Some of the loci identified include those involved in dopamine and light processing. These genetic findings provide further support for mechanisms of myopia development involving light exposure, defocus and contrast.

Despite these important findings informing potential genetic locations and mechanisms of myopia development, these studies have identified less than 5% of the variation in refractive error due to genetic variants.42 Clearly, the dramatic rise in myopia cannot be due to genetics alone, but is likely due to a combination of both genetic susceptibility and increased environmental triggers."