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.…
Assuming that it’s technically practical, the results would be very unsettling: the phone screen would look like a window with the content “behind “ the window, very far away.
Shortsightedness has become an epidemic
131–140 of 424 posts
Re: Shortsightedness has become an epidemic
#132Earlier quoted context omitted.
> 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.
The timespan is too short for evolution to have had a considerable impact.
Re: Shortsightedness has become an epidemic
#133Earlier quoted context omitted.
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.
Crooked teeth really didn't exist in the farther out past. If you look at the jawbones of Neolithic people, they all have perfectly aligned teeth. The theory is that we're not chewing hard enough food, which leads to insufficient jawbone growth as a kid, leading to not enough space for your teeth.
Re: Shortsightedness has become an epidemic
#134Earlier quoted context omitted.
This is a common figurative use of the word. The etymology comes from the Greek meaning "upon/on people", so nothing in the root connects the meaning to how something develops or spreads.
Then why not call it a "pandemic"? Shortsighteness has become a global phenomenon with more than one local maximum, hasn't it?
Re: Shortsightedness has become an epidemic
#135Quoted post unavailable.
Have you not heard about the "obesity epidemic"?
Re: Shortsightedness has become an epidemic
#136Quoted post unavailable.
According to the dictionary this is a valid use of the word 'epidemic'. It's also probably the best word to convey what is happening to a general audience.
That's circular logic because dictionaries keep changing their definition to match what ignorant people use.
Re: Shortsightedness has become an epidemic
#137Earlier quoted context omitted.
There's an amazing youtuber/creator I've been following for a while and he does exactly this. Goes into the science of what it takes, and the results are really stunning. I'd love to give something like this a try, just need time. https://www.youtube.com/watch?v=6bqBsHSwPgw Also there was a breakthrough a while ago with LED ceiling lights that mimic natural sun. I haven't heard much since their release, so I'm sure c…
The length people go to in order not to leave the house…
Unfortunately me and my partner both have our families here so moving is not an option. Being able to see decently strong light in December without having to travel would be worth a lot to me.
Re: Shortsightedness has become an epidemic
#138Earlier quoted context omitted.
According to the dictionary this is a valid use of the word 'epidemic'. It's also probably the best word to convey what is happening to a general audience.
> According to the dictionary this is a valid use of the word 'epidemic'. That's circular logic because dictionaries keep changing their definition to match what ignorant people use.
Re: Shortsightedness has become an epidemic
#139Earlier quoted context omitted.
Everyone thinks this, until they pop out a second one and there is no time or energy to do anything outside work, cook, clean, and all the baby/toddler tasks.
Huh? Walks outside with the toddler are the best. Stick him in either the stroller or bike seat and it’s the only time they sit still. Guess it’s a bit hard to combine with a baby <6 months, but eventually they should both fit.
Re: Shortsightedness has become an epidemic
#140Earlier quoted context omitted.
This is a common figurative use of the word. The etymology comes from the Greek meaning "upon/on people", so nothing in the root connects the meaning to how something develops or spreads.
Then why not call it a "pandemic"? Shortsighteness has become a global phenomenon with more than one local maximum, hasn't it?
Also, pandemic is not normally used in non medical context while epidemics is frequently used that way and was for years. The journalist probably decided to use the common words in their common meaning instead of going for obscure usages.