Given that the Nature research (above) shows that eye exercises don't seem to work, we should focus [1] on what does. Research shows more outdoor time can help with myopia. See https://onlinelibrary.wiley.com/doi/full/10.1111/aos.13403
[1] See [1] what I did there?
This is why we hackers need to install Emacs/Vim on an e-reader and use that as our dev environment... outdoors with Bluetooth keyboard every day.
I assumed outdoor time helps because your eyes spend time focusing at a greater distance. Going outside, but only to use a phone/ereader/book is likely not effective.
I think this assumption, though perhaps reasonable, is incorrect, for at least two reasons:
- There are animal model studies which vary environment brightness and show a causal relationship between darker environments and myopia. The animals in the darker experimental groups aren't reading etc, and the animals in the brighter experimental groups aren't in larger cages.
- There are studies on myopia that varied indoor lighting brightness and showed brighter lighting later/decreased myopia onset. Classroom sizes (or distances from desk to blackboard, etc) did not change. These studies also found a bunch of other variables were important including longer sleep time, and less screen time.
https://onlinelibrary.wiley.com/doi/abs/10.1111/opo.12207
It is well established that much “near work” during childhood (and even adults) contributes to myopia. Some populations are particularly vulnerable. Myopia also has a reasonable strong genetic component in humans and mice.
Classic example of gene-by-environmental interaction.
Here is a recent reference and meta-analysis:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9820324/
So much for the health benefits of building model kits and collecting stamps and coins.
Did they control for the fact that people who spend more time e.g. reading likely also spend more time indoors?
Maybe a darker environment makes it harder to see distant things, and the benefit of a brighter environment is to enable focusing on distant objects, which is presumably possible even for the poor souls confined to a small cage?
From what I have gathered, the leading hypothesis is that bright light induces dopamine production, and dopamine regulates the development of the eye. When these dopamine levels are too low, the eyeball elongates and becomes myopic.
I remember seeing a study which showed exposure to UV appears to prevent myopia as well, which is another relevant factor outdoors.
Thats been tested and its not it.
The leading hypotheses a few years back is that the outdoors is very bright. Brightness levels that cannot be easily reached indoors.
surely when we squint from bright light we are straining the eye. The idea, then, is that our development expects some amount of eye strain growing up.
This, or you could switch to an outdoors-themed wallpaper.
You belong in a basement-level late-night comedy club. No sunlight for you.
This is why myopia wasn't as much of a problem back in the Windows XP days.
https://d7hftxdivxxvm.cloudfront.net/?quality=80&resize_to=w...
any laptops with a display bright enough for this purpose?
My Fujitsu-Siemens Si1520 laptop from 2006 was usable in bright sunlight. The LCD display turned reflective and monochrome in sunlight. Text and window decorations were perfectly clear. This was a surprise, because it wasn't an advertised feature, just a side effect of the display technology.
I want this! I'd love to sit at the beach with something as readable as a Kindle (and preferably a sand-proof keyboard), but with latency fast enough that emacs or vim is usable. Is there anything close to this that I can buy?
This appeared on HN a few days ago: https://news.ycombinator.com/item?id=40456834
How does wearing sunglasses affect time outside effectiveness? Any research on that?
(Just something I've wondered since sunglasses are super prevalent)
Sunglasses are not just a fashion item they also protect your eye lens from gradual damage from UV. It may be a good compromise in the end.
Protection over a life time of exposure, whereas if you avoid myopia by age 20 you're probably good for life
Didn’t quite work in my case.
And you are not alone. I know a lot of people who got myopia after 20.
How bad? My college (8 diopters) was jealous of my "mild" 4 diopters of correction.
My understanding is that the benefit of being outdoors is the ability and opportunity to regularly focus on things at a distance that helps, so sunglasses wouldn't factor in.
It’s also exposure to natural light. Myopia jumps when kids are exposed to artificial lighting [1]. It seems some constant is hard coded into our genes to calibrate our eyes to the Sun’s light. (Artificial natural light, despite sounding like an oxymoron, can help.)
[1] https://pubmed.ncbi.nlm.nih.gov/38766340/
Yes, this is the main factor. Luminance and spectrum however are reasonable secondary factors and highlighted in the reference above.
That was the leading theory for many years that explained why adult humans today have much worse vision that humans of the not-so-distant past, but it was disproven in the last decade.
We don't yet understand why, but lack of exposure to sunlight is what causes still-developing eyes to grow incorrectly.
Isn’t that eye exercises?
The issue isn't brightness, it's distance to what you are looking at and focus on the retina. When your eyes can still bring far objects into focus, they produce a signal that causes your eyes to grow longer. https://newsroom.uw.edu/news-releases/glasses-stop-myopia-ar...
I wonder if this is something VR headsets can eventually fix by putting things at a longer focal length?
Maybe instead of a 50” screen 24” away, a 500’ screen 240’ away.
See sibling comment. If studies are right, the dominant factor is about one’s exposure to sunlight, not focal distance nor focal variation.
Do we really need VR headsets for this? Is there some material way in which just walking around outside, for free, is worse than strapping expensive electronics to your face and staying indoors?
The brightness of light is actually believed to be the main factor now. This seems a supported by animal studies, where animals are fitted with light-filtering goggles. Animals that receive brighter light develop normally, while animals that receive dimmer light develop myopia.
I recently was required to renew my glasses prescription because the other one was 2 years old (so considered expired). When I got my new prescription, my optometrist said "your vision improved". I have been spending more time outside. I have found that time on the water seems to make my vision improve. I also suspect that walking through forests and experiencing the parallax effect might function as something like a depth perception calibration. It's also worth noting that I do wear glasses, but not all the time - intentionally so I can exercise my eyes.
It's the dopamine interaction of the retina receiving outdoor lighting which changes things.
I don't think this works on astigmatism though.
Why would your eyes care about dopamine? Is it because the optic nerve is part of the brain?
The entire retina is part of the CNS, aka “the brain”. The optic nerve is therefore part of the brain.
There are dopaminergic amacrine cells within the retina and dopamine receptor much more widely.
Here is a reference with some of original citations:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2865197/#R36
This is cool, thanks for sharing!
A cursory googling led here:
[.. snip ..]
https://www.jneurosci.org/content/43/48/8231
While I can see this altering your prescription why should it improve your vision?
Isn't prescription going down the same thing as vision improving?
No, there are two separate things:
1) Your prescription.
2) What your vision is like with the best correction.
Then I'm guessing calebm misremembered what the optometrist said. Probably the optometrist said "your prescription improved" or "your prescription decreased".
"Vision improved" is a possible result of treatment. My wife has had cataract surgery--her vision in that eye certainly improved!
It also is possible to have your vision improve without treatment. I have some astigmatism, it's simply impossible to fully correct. My prescription changes a lot, it's possible for the astigmatism to be a bit less of an issue on a particular exam to the point that the best line I can read sometimes changes.
Or, if your myopia wasn't too bad and you're in your 40s, that could just be related to presbiopia. That's what seems to have happened to me, and what the ophtalmologist I was seeing when I was a teenager told me might happen.
Let us know when you have 2020 vision again.
This may be a silly question but were you spending the time outside with or without your glasses on?
Any research on this?
Why is spending time outdoors not considered an eye exercise?
It's probably similar to the difference between doing "proper" squats in a squat rack vs. using a cheater frame. The muscle movement is more varied and not as linear as doing a single left/right up/down exercise. But that's just a guess.
Is there any hard data on how much a machine impacts muscle growth/flexibility/whatever vs free weights?
I agree that free weights are probably better overall, but would love if that were quantified somehow.
isn’t it just about mind to muscle connection
The study is about a specific type of eye exercise. The translated English title makes it sounds more general than it is.
I don't think they know for sure what it is about being outdoors that helps prevent myopia. But it's thought that it might be the bright light. To me, passively taking in bright light wouldn't qualify as an exercise.
I’ve heard this is important for young kids when eyes are developing. Once the weakness is built in, there’s not much t that can be done.
But I definitely recommend this to people I know with new babies. We do a bad job consciously recognizing the difference between indoor and outdoor light, but they’re orders of magnitude different in actual brightness.
And I we don't really notice that magnitude of difference because our optical system adjusts so well
I only started understanding the difference after getting into photography.
If VR goggles have the image focal point at infinity, does that count too?
Also, what if you wear glasses that move points close by (e.g. your screen) to infinity?
Regarding your second question, that's basically what computer glasses (and reading glasses) do. They basically make things that are close, visually farther away.
For people who can't focus up close anymore (elderly), they move the book visually farther away where the eye can still focus.
When used as computer glasses, you could see the screen without the glasses, but with the glasses they are shifted farther away visually which helps with eye strain.
Ok. Can we make glasses that 1. move my screen to virtual infinity, and 2. enlarge the screen in my FOV?
23 of 25 studies were in children, and also it didn’t seem to have any effect in people who already have the problem :(
Rarely do the jokes on HN get a chuckle out of me, but you did it!
Time to give your kids headphones, boomboxes, and old-school mp3 players, everyone. Get them outside and dancing in a forest!
I had to equip my reading glasses, then I saw.
No. That hypothesis came from the fact that myopia in Australia was much rarer, but that was because they banned lead later than others.