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Shortsightedness has become an epidemic

economist.com

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Re: Shortsightedness has become an epidemic

#321

Post by sbf501 »

mgdlbp wrote: post #125
eastbound wrote: post #74

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.…

You and I and a few others around the web all have had this idea of making screens look farther away, by changing focus with positive lenses and and binocular convergence using prisms. I actually wrote this comment with the math for determining the required prescription (since you can simply order them online) just a month ago.[1] I then found that the concept isn't uncommon when I discovered an older comment with th…

Around 1995 I wrote a DirectDraw text-editor that would render two images and force you to defocus your eyes like the op-art-3d puzzles: making the viewer have to focus far away. It worked for images but not for reading small text.

Re: Shortsightedness has become an epidemic

#322

Post by Izkata »

volfied wrote: post #207
EnKopVand wrote: post #201

Earlier quoted context omitted.

The beauty of science is that you don’t have to “believe” in it.

The beauty of science is that you don't "blindly believe" in it.

Plenty of people do blindly believe it (hence the catchphrase "believe science"). Best to combine your two statements: you don't have to "blindly believe" in it.

Re: Shortsightedness has become an epidemic

#324

Post by delecti »

d0mine wrote: post #229
sandstrom wrote: post #192

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 gr…

This should be easy to answer: we are not smarter in the recent decades (the opposite is likely true due to the leaded petrol). The natural selection for smartness is too weak in humans (it does not take much brain to reproduce nowadays). The hypothesis in TFA is much more likely (regular exposure to bright daylight in children)

On the contrary, IQ has been increasing decade-over-decade basically since IQ was invented. So we are smarter in recent decades.

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

(Though because IQ is standardized around a mean of 100, it's probably more accurate to say that the IQ of people in the past has retroactively gotten lower)

Re: Shortsightedness has become an epidemic

#325

Post by Aulig »

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.

Re: Shortsightedness has become an epidemic

#326

Post by Aulig »

mgdlbp wrote: post #188
JackMorgan wrote: post #153

Earlier quoted context omitted.

You might enjoy checking out https://endmyopia.org/ There's calculators on his site also for astigmatism. I think also a list of optometrists who will understand if you want weaker lenses.

Good info on refractive error there, though I don't see much on prism lenses used for this purpose. While searching, I did discover this book, the Myopia Manual , which they're hosting a copy of. It looks quite thorough and does have a chapter on using prisms to match vergence with accommodation in plus lenses. The book also has its own site http://www.myopia-manual.de/ I also found an older myopia submission where a…

There's people in the endmyopia forum using base in prism with their plus lenses - look for espantoso and nycmao :)

Personally, I just use plus lenses without prism.

Re: Shortsightedness has become an epidemic

#328

Post by wrycoder »

jiggawatts wrote: post #19
scotty79 wrote: post #7

Could we just have rooms lit as strongly as outdoors?

There's an increasing body of good evidence that bright indoor conditions also lift mood and improve productivity, often quite noticeably. Since the pandemic and work-from-home, I've been working in a home office where an entire wall is a glass door leading to the balcony, floor to ceiling. I let the light stream in, and it's basically daylight inside. I had to get a brighter monitor (600 nit OLED), but now I just ca…

I spent 80% of my career in gloomy interior spaces with low intensity fluorescent lighting that beat with the cathode ray tube monitors' scanning.

I was much happier when I could snag a space with a window once in awhile.

Re: Shortsightedness has become an epidemic

#329

Post by _uy6i »

spiffytech wrote: post #268

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…

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…

Re: Shortsightedness has become an epidemic

#330

Post by mikewarot »

bigmealbigmeal wrote: post #172
mikewarot wrote: post #126

Pet peeve about language use: I thought it was obvious that short-sightedness (Exclusively Short term thinking) is an epidemic, nobody on Wall Street can see past the next Quarter's numbers. I don't need the economist to point that out. Nearsightedness is what this article is about... a completely different thing. I've dealt with that my entire life... and just went through the knock-on effect of retina detachment, a…

> I strongly suspect the amount of light outdoors is NOT really the issue. If you're always focused on things close at hand (as the above mentioned folks on wall street), you never allow the eyes to focus on the far horizon for an appreciable fraction of the time. Then you need to read more on the matter. Studies on chicks, tree shrews and rhesus monkeys show that simply increasing the amount of indoor light intensit…

All of the experiments you mentioned happened indoors. How can you have far field (> 100 meters distant) objects inside a laboratory? None of those experiments rule out my hypothesis.
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