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Shortsightedness has become an epidemic

economist.com

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Re: Shortsightedness has become an epidemic

#121

Post by geeB »

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 can do that cheaply by picking up a pair of reading glasses, or glasses with lower power if you are already nearsighted. Roughly, infinity will be at 1/diopters in meters, so +0.5 glasses will make 2m away at infinity, +1.0 at 1m, and so on, and similarly if you are at -3, -2.5 will make 2m infinity, etc. It's not exact because they are not thin lenses and there is a separation between lens and eye, but it should be pretty close.

I've been using one less diopter correction for a while most of the time, with an additional pair of glasses with the full prescription for driving. Not sure if it does anything or my nearsightedness just naturally stopped progressing though, but since it's working and not bothering me I have no interest in finding out.

Re: Shortsightedness has become an epidemic

#123

Post by otabdeveloper4 »

XorNot wrote: post #38
rhinoceraptor wrote: post #34

Earlier quoted context omitted.

Quoted post unavailable.

Wisdom teeth used to just be a problem that either killed you, or you lived with lots of pain from, or you paid a guy to try and do something about them. I don't know why people are so big on "we used to not need X in the distant past" tropes: yes we did, but we also just let lots of people die from it, or live a life of agony or being shunned as ugly/unclean/unable.

Only Americans are afraid of wisdom teeth. 90 percent of the rest of the world keep them with no problems whatsoever.

(Something something medical cartel...)

Re: Shortsightedness has become an epidemic

#124

Post by mattlondon »

simonh wrote: post #94
mattlondon wrote: post #57

Earlier quoted context omitted.

Good luck with the plan :) Under the age of about 1 to 1.5 then you get to call the shots of what happens when. Walk as mu h as you like. After that age, the kids start to get their own opinions and won't always just do what you want them to do. You may want to go for a long walk, but the kid wants to do something else. They'll spend 95% of the time trying to escape the buggy/stroller or trying to run off or just sit…

It very much depends on the relationship you have with your kids. Respect and trust are really important. However beyond that IMHO frankly it's critical safety imperative that children do what their parents tell them when it matters. If you're in the street near traffic a child disregarding parental instructions is a life and death issue. There are other safety critical situations too. This is why I feel it's vital t…

Your kids can trust and respect you, but they still get curious and still get bored. They won't always want to do what you want them to do, especially when they are toddlers.

You need to let kids be kids (while being safe which I obviously agree with)

Re: Shortsightedness has become an epidemic

#125

Post by mgdlbp »

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 the same idea, which I've misplaced, but a search turns up another thread revealing that this already exists as a product marketed for gaming.[2]

[1] https://news.ycombinator.com/item?id=31349629

[2] https://news.ycombinator.com/item?id=21742229

Re: Shortsightedness has become an epidemic

#126

Post by mikewarot »

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, and surgery to correct the same. Having a bubble of C3F8 gas in your one good eye is pretty damned effective at taking you out of commission for about 4 months. Looking down hurts! I hope to be up and about, and able to drive again by the start of September, once the bubble has gone, my eye has stabilized, the surgeon has made a final check, and finally after I get new glasses.

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.

I'm surprised to learn that there's no consensus on how the eye actually focuses on objects at various distances[1]. It is also well know that the smaller an iris in a camera (or eye), the larger the range of distances that appear in focus. It seems reasonable to me that if you spend your time looking at only nearby objects (like above mentioned Wall Street residents), you'll lose the ability to see things further out that might be coming to get you.

[1] - https://en.wikipedia.org/wiki/Accommodation_(eye)

Re: Shortsightedness has become an epidemic

#127

Post by lr1970 »

wiseowise wrote: post #43
rhinoceraptor wrote: post #34

Earlier quoted context omitted.

Quoted post unavailable.

> It is abnormal for humans to need glasses. It's also abnormal for humans to need braces and to need their wisdom teeth surgically removed. It's not. Just because there wasn't a documented cases of weakly sighted people doesn't mean that they didn't exist. Or do you seriously believe all prehistoric humans had 20/20 eyesight? And unless your teeth are crooked line vines you probably don't need braces from medical st…

> Or do you seriously believe all prehistoric humans had 20/20 eyesight?

The prehistoric realities were harsh and nearsighted individuals had little chances of survival and procreation (natural selection). In the modern society perfect eye-sight is not as important for survival as in the prehistoric society, thus more tolerance to its greater variability.

Re: Shortsightedness has become an epidemic

#128

Post by msk-lywenn »

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 have very bad eyesight too. May I ask what is your correction? (Not sure it’s the proper word in English, but the thing measured in dioptres?)

Re: Shortsightedness has become an epidemic

#129

Post by xioxox »

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…

Short-sightedness is the eye problem in British English: https://www.nhs.uk/conditions/short-sightedness/ We also use long-sightedness.
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