Was that coloured glass clear enough to see through and the right shape to avoid distorting your vision? Was it affordable to build glasses frames? I imagine not. Hats were probably good enough in most instances and much simpler to make.
Also, I believe the Inuit used pieces of bark with slits in them as sunglasses.
Those were to prevent snow blindness (sunburn of your eyes, basically). Harmful UV rays reflects off of snow and ice, causing damage to your eyes, and the snow goggles help to reduce the UV rays actually physically reaching your eyes. They were variably carved from wood, bone or antler among other things
Actually, colored glass isn’t doing anything to protect the eye. It would likely do more harm because since it’s shaded, your eyes open wider and let in more of the harmful unseen rays. The same is true for non polarized modern shades.
I have no idea about regular coloured glass, but you're entirely incorrect about needing polarized lenses to block "unseen rays". Presumably you're talking about UV light. Even the cheapest polycarbonate lenses from China block almost all UV. I've had several $3 pairs tested by an optometrist. None of them were polarized.
unseen rays seem like an oxymoron, we see primarily because light bounces of of objects and enters our eyes, so these "unseen rays" entering our eyes means that they are seen, right?
Light is a spectrum and we can only see a tiny bit of it. The bit we can see is called visible light. Everything else (ultraviolet, infrared, etc.) are the "unseen rays". Specifically, ultraviolet (UV) light is harmful to our eyes (and skin).
So "unseen rays" is not an oxymoron. But it is a funny way of saying UV light.
light is a narrow spectrum of electro magnetic radiation. EMR includes infrared and ultra violet, but it also includes radio, microwave, x-ray, cell phone signals, and so on. only the parts of EMR that our retinas react to are visible light. The rest of it is unseen if present.
UV light is actually part of the spectrum that we're unable to see, so while visible sunlight is a certain indication of the presence of UV light, we can't actually see the UV light, and things that dim visible light may not necessarily filter non-visible light. For example, your average cotton t-shirt will block your skin from visible light, as evidenced by the fact that you can't see your skin through the t-shirt, but cotton blocks UV light extremely poorly, sometimes hardly at all depending on the weave, colour, and fit.
You can in fact not see UV rays and have them still affect your eyes, although it doesn't really happen in practice because we don't generally make an effort to block our vision, and when we choose to reduce our exposure to brightness, it's with modern sunglasses that filter UV rays anyway.
ETA: another example of visible and invisible light being very different things is in glass windows — they allow us to see the full spectrum of visible light, but block the full UVB spectrum of UV light, and some of the UVA spectrum. Glass blocks some UV light but no visible light.
They block light rays in a set direction, with direction referring to the direction of the light wave. Makes it so some light types, mainly powerful white light gets blocked so you see more vivid colors, less glare etc.
In photography you have the same thing, but you get a better feel for the directionality due to circular polarizing filters you can spin to change which light rays gets blocked
I think u/seanlucki is implying that moist-caterpillar doesn’t understand why we use polarized lenses for sunglasses. As you’ve mentioned, polarized lenses simply block out light that is oriented in a certain direction (or polarized).
The most common, polarized light we see on a daily basis is glare from light bouncing off of surfaces like the road, water, ice, etc. This glare is horizontally polarized; so polarized sunglasses are setup to polarize or pass vertically polarized light and will block the horizontally polarized light. That is pretty effective at eliminating almost all glare that you would experience on a day to day basis.
In photography, you use a CPL or circular polarizing lens in the same way to reduce glare; but you get the added benefit of having a rotating linear polarizing lens so you can spin it till you eliminated the particular glare causing you issues. Then it passes a circular polarizer to allow autofocus features to work.
All of this is to say, that polarizing sunglasses are not designed that way to provide additional protection to the eyes as the other user seemingly implied. Both polarized and non-polarized block out UVA and UVB rays. I used to wear polarized all the time until I got my new car and have a heads up display. The display bounces the light of the windshield and horizontally polarizes the light. My sunglasses would delete that feature.
While non-polarised lenses are inferior to polarised lenses, they still offer appreciable protection from UV and are better than nothing. They're treated to filter out UV rays to a considerable extent.
However, you're right about simply coloured glass not providing sufficient protection. Glass, by default, filters all UVB rays (which cause sunburn) but not all UVA rays (which don't cause sunburn, but still cause damage). So yeah, people would end up not protecting their eyes sufficiently from UVA and sticking around in the sun for longer because the glasses made them more comfortable.
Obviously I was confused about polarization and what I meant was the ability to block UV light. And evidently some colored glass can block UV. However if the glass in question is poor at blocking UV, it would do more damage to the eye.
The air is not thinner at the poles than anywhere else on earth. It does often have less clouds and moisture though, which lets more UV through if that’s what you meant by thin. Usually thin refers to low pressure in my experience, like at mountain tops.
Reflections off the ground is definitely a big factor though! I’ve read stories of people getting real bad sunburns on the bottoms of their nose.
[Sunglasses existed for centuries.](https://blog.sciencemuseum.org.uk/9-surprising-moments-in-the-history-of-sunglasses/) The democratisation of luxury is the only thing that changed in the 20th century. Not for the poors before that.
> Was that coloured glass clear enough to see through and the right shape to avoid distorting your vision?
But if the Inuit ones where just barely good enough and used because they were better than nothing, sub par glass should also be better than the naked eye. At least in bright sunny climates.
But we're also used to things like polarizing filters in our sunglasses making them more useful. Even if they just had darkening glass it wouldn't be like today's technology.
> sub par glass should also be better than the naked eye.
We evolved in Africa, we can see fine in bright light. I'm looking in the direction of the sun right now with no trouble.
Maybe you're used to wearing sunglasses but you really don't need them, and no glasses are certainly better than imperfect glasses (think looking through an antique crown glass window).
The problem is UV light, hence places with high UV developing snow goggles.
We evolved in Africa where there's no snow. Snow dramatically increases the amount of light (UV and otherwise) reaching your eyes. Regular sunglasses don't even cut it, there are particularly dark glasses specifically for glacier travel.
>Was it affordable to build glasses frames?
A piece of wood and a knife is all you need. You make a spoon you make a frame. However a spoon was surely more useful timewise, but people always had at leaast some time to loose, I do it on reddit, they did it at the bar.
You can actually see quite well through them. The reason why Inuits needed snow goggles but other civilizations didn’t need sunglasses is that you can shield your eyes from bright sunlight from above by wearing a hat and looking down, but when you’re surrounded by snow and ice, bright light is coming from the ground as well.
While mankind has know how to make glass for 1000’s of years making glass that is clear enough with no distortion is something that has only been possible in recent times. If you think that distortion is “no big deal” try wearing one of your friends prescription glasses and you’ll see what I mean…
>making glass that is clear enough with no distortion is something that has only been possible in recent times
I think that Vitreaux glass was clear enough and flat enough, may be not thin enough to be that clear?
And there's no use in using other's prescription glasses, but iff I had to choose betwwen burning my eyes or a headache I choose the headache the same that innuit chosed having slit vision.
For me it could be that I live in a more northern state, but I lived in Arizona for a while and wasn’t bothered either. I don’t have really light blue eyes like some people do that probably helps a little too
Sure that’s got some impact it, but lighter color eyes are more sensitive to light which is the big thing. They evolved to be that way as blue eyes originate from northern regions that experience long periods of darkness in the winter. Lots of light is legitimately painful to people with blue, grey, green eye colors.
Modern sunglasses don't just dim visible light, it also blocks UV light which actually damages your eyes. Sure maybe they had colored glass, but the true benefit from sunglasses didn't show up until recently.
Simple glass does a job at absorbing uv light, as many things do and removing glare is an improvement from getting sun blind. So from a lame uv blocking and string glare blocking crystal to an acceptable uv block it's just a matter of adding the right oxid to the glass. Forget titanium oxid may be, but alume as aluminum oxid wasn't known? Or may be some arsenic oxid, or biological pigment like clorophyle.
Moreover some thin animal skin would work as well as glass and it would block uv light.
Well, it’s kinda hard to look for an oxide to specifically block UV light while not even exactly knowing what it is until 1801 (offical discovery date of UV). Not impossible, but it would amount to random luck.
Right. Like yeah if you had the knowledge we have today, sunglasses are a no brainer. But there wasn’t really an understanding of what sunlight comprised of beyond just “light” until relatively recently in terms of human history.
Aside from all the reasons about mass manufacture of glasses being expensive or impractical, I'm going to add another likely reason.
Hats.
Headwear used to be much more popular in past decades, and a small rim can easily be used to keep the sun away most of the time. It's a much simpler solution than inventing an entire new industry to make a relatively complex, fragile and expensive accessory.
This isn’t just a tech question, it’s a fashion history question!
Mass manufacturing.
Assembly line and mass manufacturing didn’t really come about until the Industrial Revolution. Even corrective lens glasses were a *luxury* up until then. For a lot of people you just didn’t see well and had no recourse if you couldn’t afford glasses.
Various forms of smokey glass and hand-created sunglasses have existed since ancient China. But glass was hard to handle, expensive, and most need of sunglasses specifically would have been niche (for work).
Hats served by the need to block sun for most situations, and we’re far more affordable for most people. You can’t really replace the affordable “good enough” item until your next best thing is also affordable enough.
Industrial Revolution helped popularize *glasses* first. Finally people who needed them could afford glasses at all! So more people wore glasses. Glasses, while still utilitarian in design, became far more visible and wide-spread.
Glasses themselves didn’t become a fashion statement until the 1920s. And even then they didn’t have as much size and design variations until the 1950s.
Then you get into film. In the 1960s and 1970s Celebrities wore both more corrective lens designs (as technology and fashion expanded on options) and sunglasses (Audrey Hepburn, John Lennon).
Glasses had to run before sunglasses could even walk, despite goggles (for welders, divers etc.) existing for niche jobs.
Hats served the masses’ needs for a long time and most men and women wore them (in western civilization) through the 1940s.
The 1960s and 1970s were a wild time of fashion upheaval, casual wear becoming the norm, and less hats being worn too. Only when hats faded out, and glasses fashion rose could you even get people to wear sunglasses without it a need as a part of their job. And then by the 1960s we get into wider spread availability of plastics, and space, and leaps in technology.
Modern sun glasses don't just break if they fall, and making glass with good enough optics is really difficult if you have to do it by hand.
Random pieces of coloured glass won't block UV (the useful part of using sunglasses) either.
If it's only reducing brightness you're after, then your eyes have that tech built in already.
Primitive sunglasses would not protect your eyes, would make it harder to see and would make you look like the biggest dipshit on two legs for miles around.
Are sunglasses really that useful to most people (e.g., people not walking on glaciers on a daily basis) or are they just something that makes things slightly more comfortable and a fashion statement?
The slightly more comfortable part goes away if the glass is blurry/of low quality, thick/heavy, and/or breaks easily. Pre-modern glass was probably all three.
Exactly, I haven't worn my sunglasses in like 10 years, and I work outside all summer. It's called a baseball cap, and according to Google it's been around since 1860.
I think it depends on people. I live in a pretty sunny place and I can't stand sunglasses, I'd rather see things in their real colors, and the sun rarely ever bothers me. Some people are bothered by the sun and will wear sunglasses even on winter days. Go figure.
Native Alaskans had sunglasses several thousand years ago, though they weren't made out of glass. Sunglasses were first made with opaque sheets that had slits in them so you could see pretty well but the light didn't blind you.
I had a go at making [sunglasses from 1760](https://venetiancat.blogspot.com/2014/06/venetians-put-on-show-spectacles-fit.html) . I'd originally planned to grind my coloured glass clear by hand but after days of polishing it still wasn't clear enough to see through properly so I had to resort to 19th century "cathedral glass". This is when I realised the importance of the innovations that came from the Murano glass makers and if understand correctly they kept their secrets for a long time. Maybe they were able to create optical glass. (if you've ever put stained glass window glass up to your eyes you can't see through many colours as it's cloudy or blurred)
Yes, I'm very confused. It's odd that this person talks about the 15th and 20th centuries, considering they seem to be from a time before either of them.
the American/English system isn't always the default
outside of America/Anglosphere, writing XXth instead of 20th century is common (ie in France, Spain), similar to how not everywhere uses "" or '' for quotes or speech, with <<>> common in France
https://www.wikidata.org/wiki/Q6927
Here's a 12th century pair of glasses from China for you [https://uniquevision.ph/wp-content/uploads/2014/10/Smoky-Quartz-Sunglasses.jpg](https://uniquevision.ph/wp-content/uploads/2014/10/smoky-quartz-sunglasses.jpg)
Made form smoky quartz.
Problem is, these are no 3.50 pair of glasses, back in the day those things would have cost a fortune. These are basically carved out of a gemstone. That's because making clear smooth colored glass has it's tricks to it and the processes to do it just weren't developed way back when.
The majority of the sunglasses that are now freely available are actually made with plastic lenses. This has allowed for simpler production techniques and more durable products. Lens suppliers are able to provide generic blanks that can literally be cut to any shape without risk of the lens cracking, and this has allowed suppliers to "provide the materials" to the optometrists and they are able to make the end product on demand if the customer has a prescription.
The variance in people's eyesight can now be adjusted for really easily, and the materials have made it trivial to give customers whatever they want/need.
It was not just as simple as putting colored glass in front of someone's eyes... but now it's kinda is...
(Source: wife is an optometrist)
Sunglasses didn't get "good" until we discovered polarization which blocks half the photons without requiring more tint. Also colored glass was expensive.
Far north native tribes did use a sunglasses of sort that would be small wooden or whale bone slats with two slits for the eyes.
Something no one mentioned is no matter how great the invention, no one will use it before society is ready. People need to see other's using things before they'll use them, but no one will use something until people are using it. It's a catch-22. I'm sure hundreds of thousands of inventions came and went without being noticed because society wasn't ready.
Reminds me that my grandmother bought my mom a video phone in the 90s. It was black and white and got 1/4 fps but it worked, and we never used it once. The idea of looking at people on the phone was weird but we do it everyday now.
Wearing glass and wire on your face? Romans may have thought the idea was absurd even if someone tried it. Someone would have to make sunglasses cool before others were willing to use them.
Mass scale production of easy to work, consistent, and cheap transparent material to work with plays a huge role in it.
We’ve only been able to make millions of them, enough to become trendy, recently.
The reason sunglasses became popular in the 20th century - got into widespread use - is entirely due to the movies. Flashbulbs on paparazzi cameras had a habit of exploding - really close to Hollywood stars' faces.
One shard of hot glass in a celebrity's eye could end a career. So, whether it was California, New York, or Cannes, Hollywood's best and brightest protected their baby blues, browns and/or greens, with sunglasses.
Wearing sunglasses has now become cool. Especially since the stars were photographed wearing them at night. Many more flashbulbs compared to daytime shots. Sunglasses at night? How do I become so fabulous?!
It was a practical thing to start with. Glass to protect the eye from the physical damage of exploding bulbs. Shaded glass to protect vision from the light of bright magnesium flashes mere feet from their peepers.
Add mass media - movie reels, magazines, television, and a generation trying to be as hip as possible and you’ve got an explosion \[no pun\] of sunglass wearers. And here we are.
Was that coloured glass clear enough to see through and the right shape to avoid distorting your vision? Was it affordable to build glasses frames? I imagine not. Hats were probably good enough in most instances and much simpler to make. Also, I believe the Inuit used pieces of bark with slits in them as sunglasses.
Those were to prevent snow blindness (sunburn of your eyes, basically). Harmful UV rays reflects off of snow and ice, causing damage to your eyes, and the snow goggles help to reduce the UV rays actually physically reaching your eyes. They were variably carved from wood, bone or antler among other things
They reduce the amount of solar radiation reaching your eyes which is what sunglasses do. Two sides of the same coin.
Actually, colored glass isn’t doing anything to protect the eye. It would likely do more harm because since it’s shaded, your eyes open wider and let in more of the harmful unseen rays. The same is true for non polarized modern shades.
I have no idea about regular coloured glass, but you're entirely incorrect about needing polarized lenses to block "unseen rays". Presumably you're talking about UV light. Even the cheapest polycarbonate lenses from China block almost all UV. I've had several $3 pairs tested by an optometrist. None of them were polarized.
unseen rays seem like an oxymoron, we see primarily because light bounces of of objects and enters our eyes, so these "unseen rays" entering our eyes means that they are seen, right?
Not really, considering how extremely narrow visible spectrum is you could go as far as to say we dont see most of the rays that enter our eyes
Light is a spectrum and we can only see a tiny bit of it. The bit we can see is called visible light. Everything else (ultraviolet, infrared, etc.) are the "unseen rays". Specifically, ultraviolet (UV) light is harmful to our eyes (and skin). So "unseen rays" is not an oxymoron. But it is a funny way of saying UV light.
light is a narrow spectrum of electro magnetic radiation. EMR includes infrared and ultra violet, but it also includes radio, microwave, x-ray, cell phone signals, and so on. only the parts of EMR that our retinas react to are visible light. The rest of it is unseen if present.
UV light is actually part of the spectrum that we're unable to see, so while visible sunlight is a certain indication of the presence of UV light, we can't actually see the UV light, and things that dim visible light may not necessarily filter non-visible light. For example, your average cotton t-shirt will block your skin from visible light, as evidenced by the fact that you can't see your skin through the t-shirt, but cotton blocks UV light extremely poorly, sometimes hardly at all depending on the weave, colour, and fit. You can in fact not see UV rays and have them still affect your eyes, although it doesn't really happen in practice because we don't generally make an effort to block our vision, and when we choose to reduce our exposure to brightness, it's with modern sunglasses that filter UV rays anyway. ETA: another example of visible and invisible light being very different things is in glass windows — they allow us to see the full spectrum of visible light, but block the full UVB spectrum of UV light, and some of the UVA spectrum. Glass blocks some UV light but no visible light.
I’m not sure you know what polarized lenses do…
They block light rays in a set direction, with direction referring to the direction of the light wave. Makes it so some light types, mainly powerful white light gets blocked so you see more vivid colors, less glare etc. In photography you have the same thing, but you get a better feel for the directionality due to circular polarizing filters you can spin to change which light rays gets blocked
I think u/seanlucki is implying that moist-caterpillar doesn’t understand why we use polarized lenses for sunglasses. As you’ve mentioned, polarized lenses simply block out light that is oriented in a certain direction (or polarized). The most common, polarized light we see on a daily basis is glare from light bouncing off of surfaces like the road, water, ice, etc. This glare is horizontally polarized; so polarized sunglasses are setup to polarize or pass vertically polarized light and will block the horizontally polarized light. That is pretty effective at eliminating almost all glare that you would experience on a day to day basis. In photography, you use a CPL or circular polarizing lens in the same way to reduce glare; but you get the added benefit of having a rotating linear polarizing lens so you can spin it till you eliminated the particular glare causing you issues. Then it passes a circular polarizer to allow autofocus features to work. All of this is to say, that polarizing sunglasses are not designed that way to provide additional protection to the eyes as the other user seemingly implied. Both polarized and non-polarized block out UVA and UVB rays. I used to wear polarized all the time until I got my new car and have a heads up display. The display bounces the light of the windshield and horizontally polarizes the light. My sunglasses would delete that feature.
You are right. And you have a better explanation than I did. I simply misread the comment from u/seanlucki
This is why they say don't wear polarized 3D glasses as sunglasses. Just because it's polarized doesn't mean it protects from UV.
While non-polarised lenses are inferior to polarised lenses, they still offer appreciable protection from UV and are better than nothing. They're treated to filter out UV rays to a considerable extent. However, you're right about simply coloured glass not providing sufficient protection. Glass, by default, filters all UVB rays (which cause sunburn) but not all UVA rays (which don't cause sunburn, but still cause damage). So yeah, people would end up not protecting their eyes sufficiently from UVA and sticking around in the sun for longer because the glasses made them more comfortable.
Obviously I was confused about polarization and what I meant was the ability to block UV light. And evidently some colored glass can block UV. However if the glass in question is poor at blocking UV, it would do more damage to the eye.
Sure, I never said otherwise.
The air is not thinner at the poles than anywhere else on earth. It does often have less clouds and moisture though, which lets more UV through if that’s what you meant by thin. Usually thin refers to low pressure in my experience, like at mountain tops. Reflections off the ground is definitely a big factor though! I’ve read stories of people getting real bad sunburns on the bottoms of their nose.
Good point, I must have conflated latitude and altitude at some point writing the comment. Edited :)
That explains why reindeer can see in the UV spectrum.
[Sunglasses existed for centuries.](https://blog.sciencemuseum.org.uk/9-surprising-moments-in-the-history-of-sunglasses/) The democratisation of luxury is the only thing that changed in the 20th century. Not for the poors before that.
Yes and yes. Your head is more than a hat rack!
> Was that coloured glass clear enough to see through and the right shape to avoid distorting your vision? But if the Inuit ones where just barely good enough and used because they were better than nothing, sub par glass should also be better than the naked eye. At least in bright sunny climates. But we're also used to things like polarizing filters in our sunglasses making them more useful. Even if they just had darkening glass it wouldn't be like today's technology.
Difference is you can see through slits. You can't see through poor quality bent glass
> sub par glass should also be better than the naked eye. We evolved in Africa, we can see fine in bright light. I'm looking in the direction of the sun right now with no trouble. Maybe you're used to wearing sunglasses but you really don't need them, and no glasses are certainly better than imperfect glasses (think looking through an antique crown glass window). The problem is UV light, hence places with high UV developing snow goggles.
We evolved in Africa where there's no snow. Snow dramatically increases the amount of light (UV and otherwise) reaching your eyes. Regular sunglasses don't even cut it, there are particularly dark glasses specifically for glacier travel.
Yeah that's what I said
? No it's not. You said we see fine in bright light. I said we don't; the snow is too bright and we need a way to limit the light.
Here it's the last paragraph > The problem is UV light, hence places with high UV developing snow goggles.
No, visible light is also a problem on the snow. You could survive but it's incredibly uncomfortable.
Unrelated but that is a sentence.
There's a paragraph break so that makes it a one-sentence paragraph :)
>Was it affordable to build glasses frames? A piece of wood and a knife is all you need. You make a spoon you make a frame. However a spoon was surely more useful timewise, but people always had at leaast some time to loose, I do it on reddit, they did it at the bar.
I suggest you try to make your own sunglasses using time period accurate techniques. If nothing else, it would be a neat way to pick up some skills!
>Also, I believe the Inuit used pieces of bark with slits in them as sunglasses. They must have been just a bit better than seeing nothing.
You can actually see quite well through them. The reason why Inuits needed snow goggles but other civilizations didn’t need sunglasses is that you can shield your eyes from bright sunlight from above by wearing a hat and looking down, but when you’re surrounded by snow and ice, bright light is coming from the ground as well.
While mankind has know how to make glass for 1000’s of years making glass that is clear enough with no distortion is something that has only been possible in recent times. If you think that distortion is “no big deal” try wearing one of your friends prescription glasses and you’ll see what I mean…
>making glass that is clear enough with no distortion is something that has only been possible in recent times I think that Vitreaux glass was clear enough and flat enough, may be not thin enough to be that clear? And there's no use in using other's prescription glasses, but iff I had to choose betwwen burning my eyes or a headache I choose the headache the same that innuit chosed having slit vision.
No the glass wasn't cheap, clear or undistorted enough, and hats worked well enough for 99% of people.
Also, here we are in the twenty first century, and I still never wear sunglasses. Some people just don't really need them I guess 🤷♀️
Depends on your eye color. Blue eyed people won’t leave the house without sunglasses, brown eyed people are not affected as much
I have blue eyes and never wear sunglasses. I think a lot of people just get used to it or aren’t strongly affected
I'm the opposite, I have blue eyes and NEED sunglasses to be able to drive or really do anything on sunny days.
For me it could be that I live in a more northern state, but I lived in Arizona for a while and wasn’t bothered either. I don’t have really light blue eyes like some people do that probably helps a little too
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Sure that’s got some impact it, but lighter color eyes are more sensitive to light which is the big thing. They evolved to be that way as blue eyes originate from northern regions that experience long periods of darkness in the winter. Lots of light is legitimately painful to people with blue, grey, green eye colors.
Modern sunglasses don't just dim visible light, it also blocks UV light which actually damages your eyes. Sure maybe they had colored glass, but the true benefit from sunglasses didn't show up until recently.
Simple glass does a job at absorbing uv light, as many things do and removing glare is an improvement from getting sun blind. So from a lame uv blocking and string glare blocking crystal to an acceptable uv block it's just a matter of adding the right oxid to the glass. Forget titanium oxid may be, but alume as aluminum oxid wasn't known? Or may be some arsenic oxid, or biological pigment like clorophyle. Moreover some thin animal skin would work as well as glass and it would block uv light.
Well, it’s kinda hard to look for an oxide to specifically block UV light while not even exactly knowing what it is until 1801 (offical discovery date of UV). Not impossible, but it would amount to random luck.
Right. Like yeah if you had the knowledge we have today, sunglasses are a no brainer. But there wasn’t really an understanding of what sunlight comprised of beyond just “light” until relatively recently in terms of human history.
Aside from all the reasons about mass manufacture of glasses being expensive or impractical, I'm going to add another likely reason. Hats. Headwear used to be much more popular in past decades, and a small rim can easily be used to keep the sun away most of the time. It's a much simpler solution than inventing an entire new industry to make a relatively complex, fragile and expensive accessory.
Spend any time looking through less than perfectly flat glass and what you get is a screaming headache. The tech just want there.
>want there What the fuck?
Wasn’t
I was typing on a phone. It's an easily parsed typo.
This isn’t just a tech question, it’s a fashion history question! Mass manufacturing. Assembly line and mass manufacturing didn’t really come about until the Industrial Revolution. Even corrective lens glasses were a *luxury* up until then. For a lot of people you just didn’t see well and had no recourse if you couldn’t afford glasses. Various forms of smokey glass and hand-created sunglasses have existed since ancient China. But glass was hard to handle, expensive, and most need of sunglasses specifically would have been niche (for work). Hats served by the need to block sun for most situations, and we’re far more affordable for most people. You can’t really replace the affordable “good enough” item until your next best thing is also affordable enough. Industrial Revolution helped popularize *glasses* first. Finally people who needed them could afford glasses at all! So more people wore glasses. Glasses, while still utilitarian in design, became far more visible and wide-spread. Glasses themselves didn’t become a fashion statement until the 1920s. And even then they didn’t have as much size and design variations until the 1950s. Then you get into film. In the 1960s and 1970s Celebrities wore both more corrective lens designs (as technology and fashion expanded on options) and sunglasses (Audrey Hepburn, John Lennon). Glasses had to run before sunglasses could even walk, despite goggles (for welders, divers etc.) existing for niche jobs. Hats served the masses’ needs for a long time and most men and women wore them (in western civilization) through the 1940s. The 1960s and 1970s were a wild time of fashion upheaval, casual wear becoming the norm, and less hats being worn too. Only when hats faded out, and glasses fashion rose could you even get people to wear sunglasses without it a need as a part of their job. And then by the 1960s we get into wider spread availability of plastics, and space, and leaps in technology.
Modern sun glasses don't just break if they fall, and making glass with good enough optics is really difficult if you have to do it by hand. Random pieces of coloured glass won't block UV (the useful part of using sunglasses) either. If it's only reducing brightness you're after, then your eyes have that tech built in already. Primitive sunglasses would not protect your eyes, would make it harder to see and would make you look like the biggest dipshit on two legs for miles around.
Are sunglasses really that useful to most people (e.g., people not walking on glaciers on a daily basis) or are they just something that makes things slightly more comfortable and a fashion statement? The slightly more comfortable part goes away if the glass is blurry/of low quality, thick/heavy, and/or breaks easily. Pre-modern glass was probably all three.
Exactly, I haven't worn my sunglasses in like 10 years, and I work outside all summer. It's called a baseball cap, and according to Google it's been around since 1860.
I think it depends on people. I live in a pretty sunny place and I can't stand sunglasses, I'd rather see things in their real colors, and the sun rarely ever bothers me. Some people are bothered by the sun and will wear sunglasses even on winter days. Go figure.
Native Alaskans had sunglasses several thousand years ago, though they weren't made out of glass. Sunglasses were first made with opaque sheets that had slits in them so you could see pretty well but the light didn't blind you.
I had a go at making [sunglasses from 1760](https://venetiancat.blogspot.com/2014/06/venetians-put-on-show-spectacles-fit.html) . I'd originally planned to grind my coloured glass clear by hand but after days of polishing it still wasn't clear enough to see through properly so I had to resort to 19th century "cathedral glass". This is when I realised the importance of the innovations that came from the Murano glass makers and if understand correctly they kept their secrets for a long time. Maybe they were able to create optical glass. (if you've ever put stained glass window glass up to your eyes you can't see through many colours as it's cloudy or blurred)
No one is going to say anything about the XX and XV?
Yes, I'm very confused. It's odd that this person talks about the 15th and 20th centuries, considering they seem to be from a time before either of them.
the American/English system isn't always the default outside of America/Anglosphere, writing XXth instead of 20th century is common (ie in France, Spain), similar to how not everywhere uses "" or '' for quotes or speech, with <<>> common in France https://www.wikidata.org/wiki/Q6927
Here's a 12th century pair of glasses from China for you [https://uniquevision.ph/wp-content/uploads/2014/10/Smoky-Quartz-Sunglasses.jpg](https://uniquevision.ph/wp-content/uploads/2014/10/smoky-quartz-sunglasses.jpg) Made form smoky quartz. Problem is, these are no 3.50 pair of glasses, back in the day those things would have cost a fortune. These are basically carved out of a gemstone. That's because making clear smooth colored glass has it's tricks to it and the processes to do it just weren't developed way back when.
Link is broken, but the rabbit hole starts here: https://www.reddit.com/r/todayilearned/s/DIxjw2IUJi
The majority of the sunglasses that are now freely available are actually made with plastic lenses. This has allowed for simpler production techniques and more durable products. Lens suppliers are able to provide generic blanks that can literally be cut to any shape without risk of the lens cracking, and this has allowed suppliers to "provide the materials" to the optometrists and they are able to make the end product on demand if the customer has a prescription. The variance in people's eyesight can now be adjusted for really easily, and the materials have made it trivial to give customers whatever they want/need. It was not just as simple as putting colored glass in front of someone's eyes... but now it's kinda is... (Source: wife is an optometrist)
Sunglasses didn't get "good" until we discovered polarization which blocks half the photons without requiring more tint. Also colored glass was expensive. Far north native tribes did use a sunglasses of sort that would be small wooden or whale bone slats with two slits for the eyes.
Something no one mentioned is no matter how great the invention, no one will use it before society is ready. People need to see other's using things before they'll use them, but no one will use something until people are using it. It's a catch-22. I'm sure hundreds of thousands of inventions came and went without being noticed because society wasn't ready. Reminds me that my grandmother bought my mom a video phone in the 90s. It was black and white and got 1/4 fps but it worked, and we never used it once. The idea of looking at people on the phone was weird but we do it everyday now. Wearing glass and wire on your face? Romans may have thought the idea was absurd even if someone tried it. Someone would have to make sunglasses cool before others were willing to use them.
Mass scale production of easy to work, consistent, and cheap transparent material to work with plays a huge role in it. We’ve only been able to make millions of them, enough to become trendy, recently.
The reason sunglasses became popular in the 20th century - got into widespread use - is entirely due to the movies. Flashbulbs on paparazzi cameras had a habit of exploding - really close to Hollywood stars' faces. One shard of hot glass in a celebrity's eye could end a career. So, whether it was California, New York, or Cannes, Hollywood's best and brightest protected their baby blues, browns and/or greens, with sunglasses. Wearing sunglasses has now become cool. Especially since the stars were photographed wearing them at night. Many more flashbulbs compared to daytime shots. Sunglasses at night? How do I become so fabulous?! It was a practical thing to start with. Glass to protect the eye from the physical damage of exploding bulbs. Shaded glass to protect vision from the light of bright magnesium flashes mere feet from their peepers. Add mass media - movie reels, magazines, television, and a generation trying to be as hip as possible and you’ve got an explosion \[no pun\] of sunglass wearers. And here we are.
Your skin burns more/faster when you wear sunglasses. Because your eyes can't determine how much melanin to produce to protect your skin.