I’m short sighted but getting on in years so instead of getting reading glasses, I peer over the top of my glasses or take them off to read. So here I am, lying in bed with my phone watching UA-cam and when Hank tapped his glasses I immediately tapped mine to see if they were plastic too and then poked myself in the eye because I’m not wearing my glasses
@@AnalistGuffy The pun is: ,,I feel your pain" as in ,,I understand your strugle" And ,,I feel your pain" as in ,,I literary feel your pain because I also poked myself in the eye"
It wasn't until i was in my late teens that I realized I needed glasses. I put on someone else's glasses at summer camp and I *could see the leaves on the trees* . I was blown away. In hindsight, I now understand why everyone in my school classes could see the board at the front, while I couldn't. Changed my life.
Same story for me, tried my friends glasses in class and I realized my eyes were fucked. Thinking back to my eyeless days its insane I couldn't tell, now I feel blind without them.
Eyes get worse, seems like it could be your parents fault for not taking you to a doctor to get your eyes checked, it’s done commonly at normal checkups for kids. Eyes could get worse at any time, especially if you’re Asian.
Glass lenses are still made and sold. And they are not that much more expensive. The biggest downside is that they make the glasses heavier. But they are also harder to scratch, which makes them excellent for me
yes that's why I used spectacles made of glasses for many years but the darn things are so heavy they left marks on both sides of my nose and used to give me headaches.
Um... Glass lenses cost 2 to 3 times as much... And they take about a month to get from any lab that still makes them. Polycarbonate is so much easier to work with.
You can have glasses made out of anything transparent. The only requirement is that they need to be made out of something with a different density than air or a vacuum.
@@crytyping. Technically you can indeed make lenses out of water--in the Middle Ages through at least the 18th century, water-filled glass globes were often used as focusing lenses for candles, for when you need a small but very bright spot of light for performing detailed work like lacemaking. (Google "lacemaker's condenser" and you'll see what I mean.)
You can actually buy a choice between polyethylene, Trivex, polycarbonate, high-index polymers, and glass. You also have choices of coatings. Some options even allow synthetic Sapphire coating, very scratch resistant.
In Germany they are still made out of glass but you can also choose plastic instead. The benefit of glass is that it's not easily scratched as plastic does, which is quite important for certain professions like archaeologists as they work in a dusty and dirty environment that can cause scratches on plastic glasses. However, the glass can break and splinter in case of accidents and the worse your eyesight gets, the thicker get's the glass. So at a certain point glass is no option as the weight would be too heavy to wear them anymore without giving you a headache.
@@goranpersson7726In sweden plastic is standard. You can special order actual glass, but it’s usually not recommended by the optician. - Optometry student here
It has to do with the curvature of the glasses. Basically, your glasses are either a convex or concave lens which focuses the light to a specific spot on your retina because the lens of our eyes can’t do it. It’s optics and it’s super dope and I love university ❤
For nearsightness, the lenses are thicker at the edge. For farsightedness they're thicker in the center. Same for contacts. For astigmatism, the curvature is different along some axis. Since astigmatism can be and often is rotated, the corrective axis is rotated to match. My optometrist explained it when I got contacts since you can distinctly feel that thicker edge. I also have astigmatism, and my contacts have a pair of orientation lines that need to be vertical or my astigmatism gets worse. Found that out by not paying attention for the first week or two. Also, since light rarely originates from a point source, your eye has a focal plane rather than a focal point. It's easier to discuss using a focal point.
@@totally_not_a_bot I see that between my glasses and my parents'. I'm farsighted but my mom is very nearsighted. We both have astigmatism, and she said to be glad they don't make hard contacts anymore. I got some for my left eye (the worse one) and she was surprised that they make soft ones now. They're weighted and it's really weird if you put it in sideways and have to get it to go upright. It's like someone took a smudge tool and wiped it across everything.
Curvature yes but you literally ignored what Hank said. It's the material which slows down light. If light is perpendicular, the angle will be the same meaning it won't slow down, but at any other angle it will. Also the curvature adds that much material slowing the light down further. So it's not just the curvature but also the distance between the entry and exit points of the path of light.
My grandpa has worn bifocals for decades, since long before I was born. One day at a family gathering, the topic came up and he revealed to the family that the main part of the lenses was actually non-prescription. It turns out that his far sight works fine and he just has them as reading glasses.
Once someone walked into me and apologized so so much because they were worried that my glasses are broken, so i told them not to worry and they asked me “but isn’t it glass?” Thank you for this video.
Unless you are in my situation, where I can see fine close up but not far away, so my glasses fuck up my near field. I tried progressive glasses. They are a fucking nuisance. The field they work for close up is TINY. It's infuriating. I'm better off peering under the rim.
@@HotelPapa100 You clearly didn’t get the right type of progressive lenses (I’m sure those you got would suit some people, but they clearly didn’t suit you). Next time, ask the optician about different types; hopefully they’ll have a graphic that shows how the lens will be split into different fields for each type. Oh, and you obviously can’t use the smallest frames, since they don’t leave much space for the reading field.
@@ragnkja The limitation of the near field being small is common to all progressive lenses. I will need new glasses for legal reasons as a glider pilot, and I sure as heck will go for bifocals. 1 part for reading the instruments, and one for looking outside. I won't go for a lens that just works in case I hold my head just right.
I work at a Specsavers in Australia so let me give you my (admittedly limited) knowledge about it. Most optical stores in first world countries will give you plastic lenses due to them being cheaper and safer. Although they scratch more easily, they're less likely to completely shatter when hit with something compared to glass (essentially, you won't end up with an eye full of plastic shards but you will end up with glass shards). We can make them out of glass, but only from customer request and it's more expensive. As for how they help you see, it's to do with the thickness and curvature of the lens. People with good long distance vision and bad short distance will need a positive prescription, meaning the lens will be convex. People with bad long distance will need a negative prescription, meaning the lens will be concave. We also take the distance between each pupil and the centre of the frame so we know where exactly to put the focal point of the lens (basically the centre of where the lens curves). Otherwise you'll be looking through the wrong part of the lens and it won't really work properly. The other most common factor in the glasses is Cyl power for astigmatism fix. Astigmatism is essentially when the eye is more oval shaped than spherical and is a very common issue (though usually not a very high Cyl power). It's tough to explain but it's essentially a much more curved "bent" lens, usually adding more thickness to the outer layer at a certain angle (which varies from person to person). There's a few other things that make up the lenses such as prisms, coatings, thinner lighter materials, etc. but it's a bit above my understanding (I just sell the shit, doesn't mean I understand all of it, that's the optoms job). Then there's the over-the-counter reading glasses you can buy at pharmacies. We heavily recommend that you get proper prescription glasses and not these ones. Most scripts I've seen in my three years of dispensing and fitting glasses have at least a slight difference in each eye and at least a small astigmatism fix. The chemist glasses have the same script in both eyes, aren't measured to your pupils, don't have any fix for astigmatism, ultimately going to either making your eyes worse or have them decline in quality at a steady rate, whereas prescription glasses can help slow the decline in eyesight due to them, you know, being made for your specific eyes. Go cheap all you want with things like food, we all love that $0.90 pasta, but eye health is not something you should scimp out on EDIT: Also forgot to mention "distance", "intermediate" and "reading" glasses. Distance glasses aren't just for people who are short sighted. They essentially just mean "for everyday wear" and can come in a positive script. These can be worn whilst driving and out and about. Intermediate is for computer use. For these ones, we add a slight power to the script and take away 1.5 mm from the pupil distance measurements. These generally give clear vision about an arms length away to a metre away. Please don't try to walk around, let alone drive in these. They will not work for that. Reading is for close up work, generally 30cm away. We add even more power, take away another 0.5 mm from the pupil distance measurements and for the love of all that is holy please never drive in these! Then there's also Bifocal and Multifocal glasses which combine them in various ways, but I've just realised I'm spending my day off talking about work so I'm gonna leave research that to you all.
Even though you warned you're not an optomitrist I'm gonna ask you my question anyway. In 1 eye I have pretty bad astigmatism (other eye's pretty good) and my bad eye goes lazy when I'm not consantrating or have been consentrating too long. Since wearing glasses (a couple of years) it doesn't seem to happen as much but if I stop wearing glasses will it go back to how it was before, get worse or just stay the same? Also you said wearing glasses can improve (or worsen) your vision, I assume that doesn't apply to astigmatism right? Surely my eyeballs not gonna change shape
@@shadowkyber2510 Thanks for asking. Ills start with your last question. from my experience, astigmatism can get worse but you yourself probably aren't gonna notice (like it shouldn't change so drastically that your eyeball pops out like a deflated beachball). Wearing prescription glasses from an optom can help slow the rate it changes and sometimes even make it get slightly better (if you've already got decent astigmatism, it's not gonna disappear but it could reduce a little, potentially). The only glasses that will worsen your vision are those cheap $3 reading glasses from the dollar store and chemists since they aren't made for your eyes. As for your bad eye, if you stop wearing your glasses long enough, I imagine the laziness will return like it was before and depending how long you go without, it could get worse. This is why wearing your glasses is so important. It not only helps you to see now, but it tends to slow how fast your eyes degrade. And here's some other things I left out of my initial post if you're interested. Typically, 3 months is the minimum amount of time it takes for your eyes to change script severely enough to notice. If you feel it's changed drastically after like a fortnight from getting your eyes checked, I'd probably say go to a doctor because that's not normal. Generally, the optometrist will determine how long your script should be good for during the test. Most prescriptions I see have 24 months until expiry, at which point you'd have to do another eye test before we're able to do anything for you in regards to new glasses (we'd be legally responsible for giving you out of date glasses if you were to have an accident). Then if the optom thinks your eyes might worsen a bit quicker than others, they can make your script yearly, 6 monthly or even 3 month check ups.
@@wolfymudkips4266 nope. You get trained on the job. You can do a certificate if you want to become a full time shop floor employee, but right now I'm a casual and I haven't had to go to any university or training location. Everything I've been taught has been from my wonderful co-workers.
I've always worn glasses but at age 45 I got my first prescription for bifocals. I refused to fill it because I felt getting bifocals was admitting I was old. A couple years later I broke down and got them. It was just too much trouble to always have to take my glasses off to see lol
Many years ago, I was told to clean my glasses by wetting each lens on both sides and then using a soft cloth or tissue to wipe the lenses. I never seem to have a scratch show up until my glasses fell off a table and bounced their way to the floor. I don't know if people are still told to do that or not.
Glasses are truly amazing! If I was born before their invention I would be sandblind and disable, but I was born in a rich country in 1991 so I can see almost normally, and I think about it quite often and feel very grateful
My dad refuses to acknowledge that hes getting older and needs reading glasses. He will pick up a socket or a wrench and hold it away from his face and try to focus his eyes like a camera on it. Amd I tell him every time, "dad please put on your readers." His response everytime word for word. "I aint outtin on no damn readers, I aint old yet." And I always tell him "dad, it dont make ya old to wear readers."
Reminds me of what Adam Savage said about having hearing aids: "having hearing aids doesn't make me feel old, NOT BEING ABLE TO HEAR makes me feel old!"
@@KeithGroover I think hes just in denial about it cause in certain lighting hes 100% fine and can see with no issues. In other lighting his vision SUCKS. But when he wears his readers in that particular lighting (mostly in our barn) and he can see for the most part. Maybe theres science behind it, maybe its somethin else idk
i used to wear glasses with glass from 2011 to 2017! I used to prefer them because they don't scratch as easily as plastic. Now changed to plastic tho, because the fatigue from the weight is just not worth it
@@jaymercer4692 I mean did you ever have your glasses shatter? also you would have the same concerns with plastic: plastic can shatter too, and although it's less sharper then shards of glass when it comes to our eyes it doesn't make a difference at all. And in fact, glasses made out of glass are even harder to scratch
@@jaymercer4692 in my 10+ years of wearing glasses i had two lenses that experienced mechanical failure of any kind: 1 lens fell out of a frame from 6' of me onto a concrete paver and a .5mm2 piece got chipped off 1 lens got a minor scratch from falling onto unsealed concrete flooring. As long as you donw throw your glasses on concrete or get into fistfights you're good.
Zeiss has this super cool glass with refractive index of 1.7, meaning it'be roughly as bulky as plastic. The only downside it's like three times more expensive then top.of the line Essilor plastics.
@@jaymercer4692 well yea 😂 probably, but any impact that could shatter your glasses is probably already too bad for your overall well being. Idk tho, worst thing happened to my glasses was just fell to the ground and had its edge chipped
My lenses are crystal. I have a strange prescription and would have exceptionally thick lenses so I get special ones. They're pretty expensive and break very easy so I do notnuse them at work
@@charliehall3823 they can adjust the base curve of the lenses to prevent this. Sometimes the glasses wearer cannot see properly or as well through them after adjusting the curve though so tread lightly.
I’ve had glasses made from glass, they are VERY heavy! Especially when the lenses are larger. 20-30 years ago I had radial keratotomy (laser surgery without lasers). I went for at least 20 years before I needed them again. It was marvelous!
i didnt have glasses for such a long time that i discovered i recognize people in the distance based on the way they move. apparently combined with certain features like length of hair that you can still spot from a distance is a really got way to tell people apart and not their faces
Progressive lenses. The great thing is you don't have to tell everyone you have them lol. But honestly though it is a normal progression of eye health. Everyone has to do it.
This feels like something most people should know... but then i realize that i only know how glasses work as well as i do because I've been wearing them since i was 5 (for reference, i am 24 rn), and my mother works for a vision care company (VSP specifically). So i just learned a lot about it, cause i haven't been able to see more than a foot in front of my face without glasses for most of my life
@@ravenite-void not everyone takes physics I guess. It feels like common knowledge to me but I’ve been wearing glasses for 4/5s of my life and I am in a STEM field, so my experiences don’t necessarily reflect the norm.
Speaking as someone who make eyeglasses for a living, here's some info... There are several types of plastic used for lenses and although the material has improved over the years, glass still has the best visual acuity. You can still get glass lenses but they are increasingly harder to find. As far as close up vision goes, you can get lenses with a magnified area at the bottom of the lens. They are called progressive lenses and they work very well especially if you are used to wearing glasses already. Don't get me started on the myriad of coatings, tints and other extras you can get on and in your lenses nowadays. An episode on Sci-Show about this would be awesome! 😊
Idk why she was saying that like she was onto something 😂 im always glad to see hank but this one feels like it's below his pay grade... glasses aren't that complicated..
I believe most of them are made from Polycarbonate which is both light, and somewhat scratch resistant. Depending on other factors in your vision, you can pay more for High Index plastic which makes the lenses thinner if you have some other issues like thick lenses for someone very nearsighted or if you have astigmatism which requires a complex correction.
I know someone with like -6 prescription and has to get the extra thin ones. And they're still thick, but mine are only like +1.25 and +0.75 plus astigmatism or something like that. Astigmatism contacts are weird though, I have them for my worse eye, and it's a very weird and disorienting process to figure out.
@@joylox True. I have astigmatism, and my glasses get thicker in the corners to compensate for it. Even with High Index lenses, they are slightly thick, but very light, so I don't really notice it too much...
A concave lens is used to correct shortsightedness (myopia), when your lens is too strong and focuses light before your retina. It curves the light outward, so the lens in the eye can focus it correctly. A convex lens is used for longsightedness (hyperopia), when the lens is too weak and focuses light behind the retina. The lens in the glasses focuses the light so that the lens in your eye can land the light on your retina.
Thank you! Someone actually knows... I was like "??? We learned that in physics back in like 7th grade or some shit? And most opticians have the models on either a poster or some other visualization for the kids who need glasses... How does someone with glasses not know?!"
@@doublem207 Because the lenses are either for seeing better far away, or for seeing better up close. We can't make magic lenses that can switch between the two. If you don't need glasses before the natural age degeneration, then congrats, regular glasses will fix that issue. For the rest of us? Take the glasses off and your regular sight is probably better than the corrected one, if the glasses don't fix it
@@lampekartoffel look it up. The reason glass/plastic/polycarbonate can "bend" the light is due to the difference in the speed of light in different media. We can alter HOW the light is bent by altering how much material it has to go through, and what the incident and refractory angles are. But it's the change in speed that gives the deflection. You're explaining what we do and Hank's explaining how we do. ETA: my brain immediately went to correction mode, too. Then I looked it up.
@@brianargo4595 I wasn't commenting on Hank? I was commenting on the original person who asked as she was also wearing glasses. And OC already commented in depth about how it actually works, I just said why I was confused by someone, especially someone who wears glasses, was confused by how glasses work...
shape and density of lenses have improved a lot over the last 30 years. My dad always had coke bottle lenses, and the first time he was able to go to contacts, and then lighter framed glasses has been one of things that actually is getting better as he gets older.
People are so dumb these days. This is almost as bad as "how does the mirror know what's behind the paper," bit. Next, when driving on a windy road: "Whats that light following us?" 🌙 PS: I learned all of this in public school
My glasses are made of glass, I paid extra because at the time I worked in industrial painting and a lot of the chemicals involved would eat through plastic glasses. Edit: I should add that if you don't have special circumstances, as I had, or are really morally aposed to plastic don't get glass glasses. They are significantly heavier. You don't think a couple of grams would do much, but the comfort level is heavily(badum tss) tied to the weight.
I used to get glass lenses in the 90s because my dad insisted, and they were SO HEAVY because they can't thin them out the same as plastic. Definitely made the switch to plastic when it was my choice. Heck, even with plastic, glasses can sometimes weigh on your nose and ears.
They don't scratch easily if you take good care of them; if you go out on a windy day (sand), and get dust on your lenses. Then, you spray them, and rub them with the microfiber cloth that they came with that you haven't washed in years.... You will get scratches. You wash them like dishes; wet them, gently massage them with liquid soap, rinse them, and pat dry (no rubbing) them with a piece of paper.
I once went to the optician and they said I was short sighted in one eye and apparently that’s the ocular jackpot because I’d have one reading eye and one long distance eye but then I went back a few years later and they said the short sighted eye was back to normal and I was sad because I wouldn’t get to wear multiple monocles
I always have my optometrist order actual glass lenses for my glasses. I've worked in optics for decades, and glass is still more resistant to surface scratches and had better optical clarity.
I'm an optician in Michigan. We use Plastic, Polycarbonate, Trivex and Hi-Index primarily. They have different pros and cons but we avoid standard plastic as much as possible because they shatter. You good sir need a progressive lenses. Allows for a distance, intermediate and reading area in a single lens. It takes a week to retrain your brain to look through the focal points but something tells me you'll understand the mission lol
@@syedam.graham5735 I would have them lower the progressive first to see if it helps. Maybe a compensated lens if your Rx and Doc ok it. You are right some people can't get it, but those are rare cases.
I’m the same way, I have to take my glasses off to read close up. I’m a paramedic and take them off to start IVs now, too. And yeah… makes me feel old too, Hank.
My glasses are still glass. It really depends on who is making them, what the Perscription is, and what you requested as options. I also suggest bifocals.
@@notinterested8452 it doesn’t state that on his channel. Even if he was sponsored erroneous or misrepresented statements would not be cool. Glasses can be made out of a number of materials. Glass, plastic, or polycarbonate are few of the possibilities.
Yep I prefer glass, as it is more resilient to scratches, therefore easier to clean them too. Generally it feels they can take more general abuse. Only thing is they aren't allowed for some sports.
The worst part you don't ever think about untill you hear it out loud. People that need glasses (myself included) are required to pay money to utilize the full potential of one our most important senses. Your sight is like 60ish percent of your incoming information to your brain. It's the ultimate "pay to win at life". If you have good eyes just imagine for a few moments what it would feel like to be told you had to pay money to "open" your eyes. Or you had to pay money to be able to read, appreciate art, watch your loved ones faces smile or cry. So many things you don't realize are tied to sight and a decent percent of the population can not do those things for free. Guess I'm saying we need better vision care/insurance.
I felt that “I am old” as I’m sitting her wearing my reading glasses! Although this is a bit unusual, I think - nearsighted people usually need reading glasses later in life than people who aren’t nearsighted. Or so they told me when they made me sign THREE separate acknowledgments when I had LASIK in my early 30’s. I turned 40 and BOOM, yep, can’t see close up anymore 🤷♀️ Whereas my mom still wears contacts and ended up needing readers at around 50.
Idk about you, Hank my man, but my glasses have been glass since I was 9 years old (when I got them) Very interesting that yours are plastic though, I imagine they are way less expensive (our lenses are 20-50 Canadian dollars, depending on the prescription and design)
I never hear of anyone having glasses actually made of glass. And the reason is simple: safety. If you trip and fall on your face with glasses actually made of glass... Let's just say you won't be needing those glasses anymore.
@@mcgoldenblade4765 I've fallen on my face a fair few times with several different pairs of glasses, and they'll pop out of the frame before they would ever break. Not that a cracked peice of plastic would be less dangerous for your eyes... Bad either way. But I've seen glasses get run over by a car, and they are definetly glass, not plastic.
polycarbonate lenses are overwhelmingly the norm in most places. you can get glass, but only by special request. the main advantage to plastic is not safety, but weight. they weigh about half as much, but they also cost more. i went to Costco for mine and they were $65 US for just the lenses.
Good for u, that ur eyes didn't got worse in almost 30 yrs. Mine did change and in like almost 10 yrs I now have had to change them 3x and soon again pretty sure.
Depends on where you are buying them from. All the online places I looked at that do low and mid cost glasses only do Polycarbonate or other plastics. To get glass glasses with lined bifocals I have to go to my Optometrist and pay the big bucks.
Hank, you have so much patience. Thank you for patiently educating people with your channel. I would not be able to keep my cool explaining things as you do. Keep up the good work man.
I think an important point to make here is that glasses are made of plastic because we can make glasses with higher refractive indexes than glass has, which allows those lenses to be thinner and lighter than the equivalent lens made of glass.
You can still get glass in many countries. I regularly have a plastic and glass pair, the plastic scratches so its nice to have a pair that is crystal clear.
I also get actual glass lenses for the scratch resistance. They are thicker (and heavier) than plastic lenses, so it's a good thing my prescription is mild, so they're still fairly thin.
The only thing that irritates me about glasses is that we have to pay for them. I didn't make my eyes be bad on purpose, I was born this way, but now I have to pay to be able to see as clearly as someone with perfect vision.
Optometrists have to be able to make a living off their service. You can't expect every profession to provide you free shit just because you were dealt a bad hand at your birth.
@@imchris5000 Not just more expensive, also hard to find. Not many companies make the blanks any more, and almost none of the major manufacturers work them. It's probably not impossible, but it's difficult.
Glass lenses are outdated and not the best option optically. Plastic (CR-39) with a premium anti-reflective coating (anti-reflective to reduce glare, improve visual clarity, and to add scratch resistance as well) is a good option for someone with a lower prescription. Someone with low vision or only one functional eye may consider polycarbonate or trivex lenses as they are more durable and impact resistant (also paired with a premium anti-reflective coating). These lenses are not only thinner, but they provide even better visual clarity for someone with a more mild to moderate prescription. Then there are your High Index type lenses (i.e. they have a high refraction index). These lenses are good for those with higher prescriptions (typically greater than a +/- 4.00) as they provide not only the best clarity, but they provide the thinnest possible lenses for people with higher prescriptions who would normally have thicker lenses. For Hank's issue of not being able to see up close, it sounds like you need a multifocal (whether that be a lined bi-focal, lined tri-focal, progressive / aka no-line, or some sort of accommodation lens) - [this is not a diagnosis of any sort as I am not a licensed doctor of any kind, but rather this is a suggestion of what to talk with your optometrist about as it could be a possibility that you need a multifocal.. that is for you and your optometrist to discuss!] I'd recommend seeing your optometrist to address the issues you are having as it may be something simple or even more complex.
It's also a part due to the curvature of the glasses. The refractive index (how much the material bends light) and the curvature of the lens works together
Actually, the most common material for glasses is either yes, plastic or poly carbonate, which is more Impact resistant, and better for kids and also lighter weight
Hank's eyeglass lenses seem to be CR-39 (cheap plastic) with zero "up grades"; anti-glare, anti-scratch, etc... But them at Warby Parker; polycarbonate vs with anti-reflective and anti-scratch coatings included. CR-39 has day plastic look to them. The rest are made from polycarbonate, or high index "plastic".
Ok, burst bubble here. I'm older than you by 2 years, I believe. And for the last 6 eye Dr visits, I am pissing them off... so much so that I had to switch Dr's. Each time I've improved astigmatism gone, 4.50, 4.25, 4.00, 3.75, 3.50. In Dec I could have gone down to 3.25, but we decided to wait. Also, I hobby without glasses: fiber arts (cross stitch, hand sow, and embroidery a little) So they tell me I'm ananomaly.
Oh great so I didn't 500€ for glass that made my eyes relax (cause they're not looking in the same direction.. yey?) I SPEND 500€ ON PLASTIC and I already had the frame TwT Ag least it doesn't break that fast(?)
Glasses are made of CR-39 or Polycarbonate which have refractive index of 1.49 and 1.55, higher refractive index means you can make thinner glasses and it can go as high as 1.8 but usually 1.67 and 1.74, hither gives thinner glasses but introduces chromatic abborations on pherifery.
Crown glass is still really common. Not the majority anymore, though, as CR-39 is practically equal or better than glass, but much lighter weight. Glass is actually a really good option. It is the cheapest, and provides the best optical quality. The only real downside is weight. I believe income shouldn't decide whether someone's child can see the world and thrive or not. If you buy a pair of prescription glasses, most of the cost is in the frame, not the blanks. So basically, you're paying €100+ for an expensive piece of cut sheet metal, or worse, plastic, while paying about €15 for the lens blanks. (On that note, Hank, tell us why, and how the monopoly of a major company is responsible for low income families to not have access to adequate visual aids.)
To your “someone save me” ✋ don’t shoot the messenger here - but - stop eating chicken, you’re most likely allergic. Give up chicken, eggs, certain breads, certain pastas, cakes, anything made with eggs, etc. you’ll likely find within a year your eye sight will drastically improve. Again, ✋ don’t shoot the messenger, you did say “someone save me” so, 🤷🏻♀️ just sayin’
I had glasses made of glass when I was in grade school, into high school. Durable, high index optical plastics didn't yet exist in the 1960s and 1970s. Then in 1976, I got contacts (hard lenses only in those days), and wore glasses only before putting them in, and after taking them out. By the time I gave up contacts (2006) it was impossible to buy glasses made of glass; the only choice was regular plastic or high index (made the lenses thinner but had more chromatic aberration, for which the solution was smaller lenses). As far as old, the best solutions I know of are bifocals, or two pairs of glasses (I use both -- single vision distance glasses, for driving and things like watching TV or movies in a theater, and bifocals with a computer prescription, because I do close work all day and regular bifocals won't focus close enough). Some folks get Lasik, with one eye for distance and the other for close-up (like reading), but I'll pass, thanks.
Your nicer more expensive sunglasses will have glass lenses them. Some people will have glass put into their daily pair as well, I have several. Glass is an optically superior material, just expensive to manufacture, fragile in comparison to other materials, and harder to make thinner at higher prescriptions. Each material DOES have its own index of refraction. Air has an index of refraction of 1.53. Plastic 1.59, then we have a material called high index plastic which has an index of refraction from 1.6-1.74 in the US, however you can get it at higher index and thinner materials in places like India and China due to regulations preventing us from accessing here. If you have a small or average RX, you should consider lenses made from Trivex, as it has an index of refraction of 1.53, the same as air. It is impact resistant similar to polycarbonate but without the compromise optically. - Former Optician
Thank God it's plastic. I'm SUPER farsighted, so my glasses are really thick. Only half as thick as they could be, though, since I use what's called high index lenses. Imagine how heavy they'd be if they were made out of glass. I'd need a neck brace just to hold my head up.
Unless you had very old weird glasses they are all plastic?? Really?? Why is it that that uptil 5 years ago I specifically had to tick the "plastic" option otherwise I would get glass instead? We are talking about an "average Joe" optometrist in town, not an obscure one. Fact is: every decent optometrist offers you the option to choose glass over plastic. You're knowledgable for sure. But some subjects you're just assuming, based upon nothing other than your own thoughts
Plastic= cheap, hard to break and lightweight. Cons: scratches! Dont last for long . Glass= more expensive and heavier, breaks easily, pros: no scratches! Last very long.
Hank, you're smart, you know life expectancy only keeps going up. 42 is not old, not even middle aged yet, 42 is the new 22 😂. But also consider yourself lucky you don't need bifocals. Yet.
I literally said plastic and tapped my glasses right before hank did 😂
i was just about to comment this cause i did it as well
Same lol
I tried to tap my glasses after he did, but I’m not wearing them so I just stabbed my eye 😂
It's like the click the tongs thing. You gotta do it, if you don't maybe you're a psychopath
Thats so awesome dude
I’m short sighted but getting on in years so instead of getting reading glasses, I peer over the top of my glasses or take them off to read. So here I am, lying in bed with my phone watching UA-cam and when Hank tapped his glasses I immediately tapped mine to see if they were plastic too and then poked myself in the eye because I’m not wearing my glasses
Oh, I feel your pain
Edit: Apparently my joke is not a pun, so I edit my comment to keep people out of confusion
@@lunarmothcat what’s the pun
@@AnalistGuffyyou can't see it 😉
@@AnalistGuffy The pun is:
,,I feel your pain" as in ,,I understand your strugle"
And ,,I feel your pain" as in ,,I literary feel your pain because I also poked myself in the eye"
I did the same thing 😂
It wasn't until i was in my late teens that I realized I needed glasses. I put on someone else's glasses at summer camp and I *could see the leaves on the trees* . I was blown away. In hindsight, I now understand why everyone in my school classes could see the board at the front, while I couldn't. Changed my life.
Same story for me, tried my friends glasses in class and I realized my eyes were fucked. Thinking back to my eyeless days its insane I couldn't tell, now I feel blind without them.
I don’t remember being able to see without glasses, since I started wearing them when I was seven
Eyes get worse, seems like it could be your parents fault for not taking you to a doctor to get your eyes checked, it’s done commonly at normal checkups for kids. Eyes could get worse at any time, especially if you’re Asian.
The moment I first saw leaves on a tree after I first got glasses was life changing. So beautiful, so much more movement in the wind.
Time for progressives.
Glass lenses are still made and sold. And they are not that much more expensive. The biggest downside is that they make the glasses heavier. But they are also harder to scratch, which makes them excellent for me
yes that's why I used spectacles made of glasses for many years but the darn things are so heavy they left marks on both sides of my nose and used to give me headaches.
They are also more prone to shattering, if you play basketball or soccer etc. they're a bad idea. But I too use glass lenses.
Um... Glass lenses cost 2 to 3 times as much... And they take about a month to get from any lab that still makes them. Polycarbonate is so much easier to work with.
@@sghouston I get them pretty easily but it might be a regional thing. And not that more expensive "only" about 10-15%
Yeah hugely thick GODD I used to hate having to wear them.
You can have glasses made out of anything transparent. The only requirement is that they need to be made out of something with a different density than air or a vacuum.
Water.
index of refraction (the ratio of the speed of light in that material to the speed of light in a vacuum), not density.
@@crytyping. Technically you can indeed make lenses out of water--in the Middle Ages through at least the 18th century, water-filled glass globes were often used as focusing lenses for candles, for when you need a small but very bright spot of light for performing detailed work like lacemaking. (Google "lacemaker's condenser" and you'll see what I mean.)
jello glasses
@@crytyping.as long as it doesnt melt away you can have water glasses
You can actually buy a choice between polyethylene, Trivex, polycarbonate, high-index polymers, and glass. You also have choices of coatings. Some options even allow synthetic Sapphire coating, very scratch resistant.
In Germany they are still made out of glass but you can also choose plastic instead. The benefit of glass is that it's not easily scratched as plastic does, which is quite important for certain professions like archaeologists as they work in a dusty and dirty environment that can cause scratches on plastic glasses. However, the glass can break and splinter in case of accidents and the worse your eyesight gets, the thicker get's the glass. So at a certain point glass is no option as the weight would be too heavy to wear them anymore without giving you a headache.
you must be indiana jones to make those connections lmao
pretty sure over here in Sweden it's still mainly glass aswell
But they crack and you can coat plastic glasses in scratch proof stuff
@@goranpersson7726In sweden plastic is standard. You can special order actual glass, but it’s usually not recommended by the optician.
- Optometry student here
@@harrybostrom5228 aight, mine are glass and have always been, never really investigated someone else's glasses
It has to do with the curvature of the glasses. Basically, your glasses are either a convex or concave lens which focuses the light to a specific spot on your retina because the lens of our eyes can’t do it. It’s optics and it’s super dope and I love university ❤
For nearsightness, the lenses are thicker at the edge. For farsightedness they're thicker in the center. Same for contacts. For astigmatism, the curvature is different along some axis. Since astigmatism can be and often is rotated, the corrective axis is rotated to match.
My optometrist explained it when I got contacts since you can distinctly feel that thicker edge. I also have astigmatism, and my contacts have a pair of orientation lines that need to be vertical or my astigmatism gets worse. Found that out by not paying attention for the first week or two.
Also, since light rarely originates from a point source, your eye has a focal plane rather than a focal point. It's easier to discuss using a focal point.
@@totally_not_a_bot I see that between my glasses and my parents'. I'm farsighted but my mom is very nearsighted. We both have astigmatism, and she said to be glad they don't make hard contacts anymore. I got some for my left eye (the worse one) and she was surprised that they make soft ones now. They're weighted and it's really weird if you put it in sideways and have to get it to go upright. It's like someone took a smudge tool and wiped it across everything.
Cool, but the question is about the material. You fail.
Curvature yes but you literally ignored what Hank said. It's the material which slows down light. If light is perpendicular, the angle will be the same meaning it won't slow down, but at any other angle it will. Also the curvature adds that much material slowing the light down further. So it's not just the curvature but also the distance between the entry and exit points of the path of light.
@@LukeBillwalker86 she asked “what’s in the glasses” not “what is it made of.” OP answered better than the video.
My grandpa has worn bifocals for decades, since long before I was born. One day at a family gathering, the topic came up and he revealed to the family that the main part of the lenses was actually non-prescription. It turns out that his far sight works fine and he just has them as reading glasses.
Why is Hank always looking around like the info he is about to give us is going to get him busted by the cops🤔 😂
Sounds like ADHD. I wonder if that's why ADHD kids gets in trouble more often, aside from a tendency to be louder.
In this point in time it might. You have to be careful stating basic facts nowadays
Nah it’s not the cops it’s the Illuminati. They want to keep us uneducated😂
@@donaldkeyes9799 Facts!
I love being able to turn off the HD and make up what I think the world should look like when I am bored.😂
I love turning off the HD and looking 10 years younger when looking into the mirror 😂
RTX off
Some foods i can only look at in 244p otherwise the extra details weird me out. Did you know rice was individual grains and not some white blob
bro turning off rtx in game
This is literally what I’ve been doing forever but I never thought of it that way and it’s amazing
Once someone walked into me and apologized so so much because they were worried that my glasses are broken, so i told them not to worry and they asked me “but isn’t it glass?” Thank you for this video.
Lol what?
Why is this happening so much? Are people walking into you, or are you walking into them? lol
This never happened, let alone more than once. Thank you for this comment.
@@HexJK and you know this how?
@@HexJKa destroyer of fun, just doing their duty
Dispensing optician here. Hank you need a progressive lens, which allows you to see both far away and close up 😊
Unless you are in my situation, where I can see fine close up but not far away, so my glasses fuck up my near field. I tried progressive glasses. They are a fucking nuisance. The field they work for close up is TINY. It's infuriating. I'm better off peering under the rim.
That's a thing!?
@@HotelPapa100
You clearly didn’t get the right type of progressive lenses (I’m sure those you got would suit some people, but they clearly didn’t suit you). Next time, ask the optician about different types; hopefully they’ll have a graphic that shows how the lens will be split into different fields for each type. Oh, and you obviously can’t use the smallest frames, since they don’t leave much space for the reading field.
@@ragnkja The limitation of the near field being small is common to all progressive lenses. I will need new glasses for legal reasons as a glider pilot, and I sure as heck will go for bifocals. 1 part for reading the instruments, and one for looking outside. I won't go for a lens that just works in case I hold my head just right.
@@HotelPapa100
That sounds like a good plan.
I work at a Specsavers in Australia so let me give you my (admittedly limited) knowledge about it. Most optical stores in first world countries will give you plastic lenses due to them being cheaper and safer. Although they scratch more easily, they're less likely to completely shatter when hit with something compared to glass (essentially, you won't end up with an eye full of plastic shards but you will end up with glass shards). We can make them out of glass, but only from customer request and it's more expensive.
As for how they help you see, it's to do with the thickness and curvature of the lens. People with good long distance vision and bad short distance will need a positive prescription, meaning the lens will be convex. People with bad long distance will need a negative prescription, meaning the lens will be concave. We also take the distance between each pupil and the centre of the frame so we know where exactly to put the focal point of the lens (basically the centre of where the lens curves). Otherwise you'll be looking through the wrong part of the lens and it won't really work properly.
The other most common factor in the glasses is Cyl power for astigmatism fix. Astigmatism is essentially when the eye is more oval shaped than spherical and is a very common issue (though usually not a very high Cyl power). It's tough to explain but it's essentially a much more curved "bent" lens, usually adding more thickness to the outer layer at a certain angle (which varies from person to person). There's a few other things that make up the lenses such as prisms, coatings, thinner lighter materials, etc. but it's a bit above my understanding (I just sell the shit, doesn't mean I understand all of it, that's the optoms job).
Then there's the over-the-counter reading glasses you can buy at pharmacies. We heavily recommend that you get proper prescription glasses and not these ones. Most scripts I've seen in my three years of dispensing and fitting glasses have at least a slight difference in each eye and at least a small astigmatism fix. The chemist glasses have the same script in both eyes, aren't measured to your pupils, don't have any fix for astigmatism, ultimately going to either making your eyes worse or have them decline in quality at a steady rate, whereas prescription glasses can help slow the decline in eyesight due to them, you know, being made for your specific eyes. Go cheap all you want with things like food, we all love that $0.90 pasta, but eye health is not something you should scimp out on
EDIT: Also forgot to mention "distance", "intermediate" and "reading" glasses. Distance glasses aren't just for people who are short sighted. They essentially just mean "for everyday wear" and can come in a positive script. These can be worn whilst driving and out and about.
Intermediate is for computer use. For these ones, we add a slight power to the script and take away 1.5 mm from the pupil distance measurements. These generally give clear vision about an arms length away to a metre away. Please don't try to walk around, let alone drive in these. They will not work for that.
Reading is for close up work, generally 30cm away. We add even more power, take away another 0.5 mm from the pupil distance measurements and for the love of all that is holy please never drive in these!
Then there's also Bifocal and Multifocal glasses which combine them in various ways, but I've just realised I'm spending my day off talking about work so I'm gonna leave research that to you all.
Even though you warned you're not an optomitrist I'm gonna ask you my question anyway.
In 1 eye I have pretty bad astigmatism (other eye's pretty good) and my bad eye goes lazy when I'm not consantrating or have been consentrating too long. Since wearing glasses (a couple of years) it doesn't seem to happen as much but if I stop wearing glasses will it go back to how it was before, get worse or just stay the same?
Also you said wearing glasses can improve (or worsen) your vision, I assume that doesn't apply to astigmatism right? Surely my eyeballs not gonna change shape
@@shadowkyber2510 Thanks for asking. Ills start with your last question. from my experience, astigmatism can get worse but you yourself probably aren't gonna notice (like it shouldn't change so drastically that your eyeball pops out like a deflated beachball). Wearing prescription glasses from an optom can help slow the rate it changes and sometimes even make it get slightly better (if you've already got decent astigmatism, it's not gonna disappear but it could reduce a little, potentially). The only glasses that will worsen your vision are those cheap $3 reading glasses from the dollar store and chemists since they aren't made for your eyes.
As for your bad eye, if you stop wearing your glasses long enough, I imagine the laziness will return like it was before and depending how long you go without, it could get worse. This is why wearing your glasses is so important. It not only helps you to see now, but it tends to slow how fast your eyes degrade.
And here's some other things I left out of my initial post if you're interested.
Typically, 3 months is the minimum amount of time it takes for your eyes to change script severely enough to notice. If you feel it's changed drastically after like a fortnight from getting your eyes checked, I'd probably say go to a doctor because that's not normal. Generally, the optometrist will determine how long your script should be good for during the test. Most prescriptions I see have 24 months until expiry, at which point you'd have to do another eye test before we're able to do anything for you in regards to new glasses (we'd be legally responsible for giving you out of date glasses if you were to have an accident). Then if the optom thinks your eyes might worsen a bit quicker than others, they can make your script yearly, 6 monthly or even 3 month check ups.
This was very informative. Did u need a degree of any kind to work on the store floor? I've always wondered
@@wolfymudkips4266 nope. You get trained on the job. You can do a certificate if you want to become a full time shop floor employee, but right now I'm a casual and I haven't had to go to any university or training location. Everything I've been taught has been from my wonderful co-workers.
I've always worn glasses but at age 45 I got my first prescription for bifocals. I refused to fill it because I felt getting bifocals was admitting I was old. A couple years later I broke down and got them. It was just too much trouble to always have to take my glasses off to see lol
At 45 you are extremely old. Basically a dinosaur.
Progressive contacts are where it’s at! 😊
@@mentak2593 I didn't know they existed!
if it makes you feel better I've had bifocals since i was 12 😶
@@echolotaliabrokenflight7279 Oh wow. It does put it in perspective!
glasses are so common that even though they are non-body objects i never question it anymore as if it's a part of the body.
@@bridgerparker4275 i don't know whether that is supposed to be good or bad
Like clothes?
@@EnchWraits well.. kinda everyone wears atleast some clothes depending on where you're from but not everyone wears glasses!
Curiously, wearing corrective lenses, whether glasses or contact lenses, is explicitly *not* for legal purposes, a "disability", in the US at least.
Hank, you are not old, you are distinguished. You are amazing!
He’s distinguished and old but that’s okay I think
Hank looking out the window like the CEyeA is going to be after him for revealing how glasses work
Looking like a hood dude doing an interview 😂
So many of his videos have this energy lol like it’s highly sensitive information and he shouldn’t even be talking to you
What the hell is a "CEyeA" 😭
I do buy glasses made of glass. They dont scratch so often. Luckily in my case they are not so heavy.
Yeah it's always an option, specially with the more expensive ones
Resin is only standard cause it's light and nier indestructible
Many years ago, I was told to clean my glasses by wetting each lens on both sides and then using a soft cloth or tissue to wipe the lenses. I never seem to have a scratch show up until my glasses fell off a table and bounced their way to the floor.
I don't know if people are still told to do that or not.
in my experience it's quite difficult to scratch glasses with plastic lenses if they've got a great anti-scratch coating, too.
Bifocals, Hank! You need bifocals!
You're officially old if you own bifocals
When you get really into glasses you start to learn the difference between Polycarbonate lenses, CR39 lenses, and Trivex
Lol are you an optician Mike?
Yeah man drop that deep glasses lore
Glasses are truly amazing! If I was born before their invention I would be sandblind and disable, but I was born in a rich country in 1991 so I can see almost normally, and I think about it quite often and feel very grateful
💜💜💜
❤❤❤❤
😅 😂😂
Being nearsighted was a rare condition when people got regular exposure to natural light and didn't focus on near objects for long periods of time...
🧡🧡🧡
My dad refuses to acknowledge that hes getting older and needs reading glasses. He will pick up a socket or a wrench and hold it away from his face and try to focus his eyes like a camera on it. Amd I tell him every time, "dad please put on your readers." His response everytime word for word. "I aint outtin on no damn readers, I aint old yet." And I always tell him "dad, it dont make ya old to wear readers."
tell him "ye but when your body can't handle the cold, you DO wear clothes, don't you?"
Reminds me of what Adam Savage said about having hearing aids: "having hearing aids doesn't make me feel old, NOT BEING ABLE TO HEAR makes me feel old!"
@@KeithGroover I think hes just in denial about it cause in certain lighting hes 100% fine and can see with no issues. In other lighting his vision SUCKS. But when he wears his readers in that particular lighting (mostly in our barn) and he can see for the most part. Maybe theres science behind it, maybe its somethin else idk
@@synshenron798 What accent should I be reading this in?
i used to wear glasses with glass from 2011 to 2017! I used to prefer them because they don't scratch as easily as plastic. Now changed to plastic tho, because the fatigue from the weight is just not worth it
Also would there not be safety concerns with the glass shattering at all?
@@jaymercer4692 I mean did you ever have your glasses shatter? also you would have the same concerns with plastic: plastic can shatter too, and although it's less sharper then shards of glass when it comes to our eyes it doesn't make a difference at all. And in fact, glasses made out of glass are even harder to scratch
@@jaymercer4692 in my 10+ years of wearing glasses i had two lenses that experienced mechanical failure of any kind:
1 lens fell out of a frame from 6' of me onto a concrete paver and a .5mm2 piece got chipped off
1 lens got a minor scratch from falling onto unsealed concrete flooring.
As long as you donw throw your glasses on concrete or get into fistfights you're good.
Zeiss has this super cool glass with refractive index of 1.7, meaning it'be roughly as bulky as plastic. The only downside it's like three times more expensive then top.of the line Essilor plastics.
@@jaymercer4692 well yea 😂 probably, but any impact that could shatter your glasses is probably already too bad for your overall well being. Idk tho, worst thing happened to my glasses was just fell to the ground and had its edge chipped
Rainie is going to be stoked when she sees this!
Do you know where that clip is from?
@@SirAndrew00 Try guys podcast. Rainie is one of their producers and she’s my favourite
She's gonna freak out!!!
That's what I was thinking when I saw this :)
My lenses are crystal. I have a strange prescription and would have exceptionally thick lenses so I get special ones. They're pretty expensive and break very easy so I do notnuse them at work
Four digit number$?
My brother's prescription is so thick, his eyelashes constantly sit on them.
@@michaeldriver127 6-10k
@@charliehall3823 they can adjust the base curve of the lenses to prevent this. Sometimes the glasses wearer cannot see properly or as well through them after adjusting the curve though so tread lightly.
@@gillsejusbates6938 I....... see😳
I’ve had glasses made from glass, they are VERY heavy! Especially when the lenses are larger. 20-30 years ago I had radial keratotomy (laser surgery without lasers). I went for at least 20 years before I needed them again. It was marvelous!
Glasses are amazing. Imagine just having the world be blurry for a ton of people… not fun.
dont need to... Spent 30 years of my life with 0 Depth perception. Getting glasses was literally me seeing the real world for the first time.
i didnt have glasses for such a long time that i discovered i recognize people in the distance based on the way they move. apparently combined with certain features like length of hair that you can still spot from a distance is a really got way to tell people apart and not their faces
@@jordanekl5383 goodness, I’m glad you got them!
@@Arthera0 that’s impressive, yet I’m very glad you got glasses
You should get multi focal lenses. My lenses have close, middle and long range sections without any visible lines
Progressive lenses. The great thing is you don't have to tell everyone you have them lol. But honestly though it is a normal progression of eye health. Everyone has to do it.
"There's a bird! There's a plane! There's Alpha Centauri!"
-Brian Regan
*Watching while laying in bed
*picks up glasses...
*tap-tap...
*puts back glasses
*continues watching
This feels like something most people should know... but then i realize that i only know how glasses work as well as i do because I've been wearing them since i was 5 (for reference, i am 24 rn), and my mother works for a vision care company (VSP specifically). So i just learned a lot about it, cause i haven't been able to see more than a foot in front of my face without glasses for most of my life
Isn't that like highschool physics? Or even lower grades?
@@ravenite-voidi’ve never learned that in school… am 20
@@ravenite-void not everyone takes physics I guess.
It feels like common knowledge to me but I’ve been wearing glasses for 4/5s of my life and I am in a STEM field, so my experiences don’t necessarily reflect the norm.
We learned this in school when i was +-8 years old.... Its basic information for everyone
@@Ian-bf4yk in my country you can't choose physics, it's mandatory
Speaking as someone who make eyeglasses for a living, here's some info... There are several types of plastic used for lenses and although the material has improved over the years, glass still has the best visual acuity. You can still get glass lenses but they are increasingly harder to find.
As far as close up vision goes, you can get lenses with a magnified area at the bottom of the lens. They are called progressive lenses and they work very well especially if you are used to wearing glasses already. Don't get me started on the myriad of coatings, tints and other extras you can get on and in your lenses nowadays.
An episode on Sci-Show about this would be awesome! 😊
Idk why she was saying that like she was onto something 😂 im always glad to see hank but this one feels like it's below his pay grade... glasses aren't that complicated..
I believe most of them are made from Polycarbonate which is both light, and somewhat scratch resistant. Depending on other factors in your vision, you can pay more for High Index plastic which makes the lenses thinner if you have some other issues like thick lenses for someone very nearsighted or if you have astigmatism which requires a complex correction.
Yep, polycarbonate! My dad always paid extra to get real glass because he could see through them better.
I know someone with like -6 prescription and has to get the extra thin ones. And they're still thick, but mine are only like +1.25 and +0.75 plus astigmatism or something like that. Astigmatism contacts are weird though, I have them for my worse eye, and it's a very weird and disorienting process to figure out.
@@joylox True. I have astigmatism, and my glasses get thicker in the corners to compensate for it. Even with High Index lenses, they are slightly thick, but very light, so I don't really notice it too much...
WOO! Astigmatism gang! My glasses always looked weird asf.
yup, polycarb with a blue light filter coating, other pair is polycarb transitions.
I feel ya brother, 48 now and stuff is starting to wear out, need maintenance
Hank is looking out for corporate-hired snipers who're after him because he knew a little too much about the big glass.
A concave lens is used to correct shortsightedness (myopia), when your lens is too strong and focuses light before your retina. It curves the light outward, so the lens in the eye can focus it correctly.
A convex lens is used for longsightedness (hyperopia), when the lens is too weak and focuses light behind the retina. The lens in the glasses focuses the light so that the lens in your eye can land the light on your retina.
Thank you! Someone actually knows...
I was like "??? We learned that in physics back in like 7th grade or some shit? And most opticians have the models on either a poster or some other visualization for the kids who need glasses... How does someone with glasses not know?!"
Why can't we do sth for the other thing Hank mentioned, he is old so he can't look close up? My dad has the same issue.
@@doublem207 Because the lenses are either for seeing better far away, or for seeing better up close. We can't make magic lenses that can switch between the two.
If you don't need glasses before the natural age degeneration, then congrats, regular glasses will fix that issue. For the rest of us? Take the glasses off and your regular sight is probably better than the corrected one, if the glasses don't fix it
@@lampekartoffel look it up. The reason glass/plastic/polycarbonate can "bend" the light is due to the difference in the speed of light in different media. We can alter HOW the light is bent by altering how much material it has to go through, and what the incident and refractory angles are. But it's the change in speed that gives the deflection. You're explaining what we do and Hank's explaining how we do.
ETA: my brain immediately went to correction mode, too. Then I looked it up.
@@brianargo4595 I wasn't commenting on Hank? I was commenting on the original person who asked as she was also wearing glasses. And OC already commented in depth about how it actually works, I just said why I was confused by someone, especially someone who wears glasses, was confused by how glasses work...
shape and density of lenses have improved a lot over the last 30 years. My dad always had coke bottle lenses, and the first time he was able to go to contacts, and then lighter framed glasses has been one of things that actually is getting better as he gets older.
People are so dumb these days. This is almost as bad as "how does the mirror know what's behind the paper," bit.
Next, when driving on a windy road: "Whats that light following us?" 🌙
PS: I learned all of this in public school
Sounds like it's time to consider bifocals. Works for me.
Yes! You finally responded to Rainie 😍 can't wait to hear the Trypod responding to this
I dunno what any of thst means but she hawt. Got her r4r handle?
My glasses are made of glass, I paid extra because at the time I worked in industrial painting and a lot of the chemicals involved would eat through plastic glasses.
Edit: I should add that if you don't have special circumstances, as I had, or are really morally aposed to plastic don't get glass glasses. They are significantly heavier. You don't think a couple of grams would do much, but the comfort level is heavily(badum tss) tied to the weight.
I used to get glass lenses in the 90s because my dad insisted, and they were SO HEAVY because they can't thin them out the same as plastic. Definitely made the switch to plastic when it was my choice. Heck, even with plastic, glasses can sometimes weigh on your nose and ears.
It used to be that photogray could only be added to glass lenses as well. I had glass lenses then, too
It's called bifocals, Hank. We all eventually need them. Aging doesn't stop for anyone.
Bro was looking around like there was a horde of zombies outside his window, and decided to make a TikTok instead of any attempts to escape.😊
Bifocals aren't that bad. It didn't take very long to get used to them and now I love them.
My old lenses were glass (got em, like, 17 years ago? ). I miss them. Plastic lenses are so easily scratched.
They don't scratch easily if you take good care of them; if you go out on a windy day (sand), and get dust on your lenses. Then, you spray them, and rub them with the microfiber cloth that they came with that you haven't washed in years.... You will get scratches.
You wash them like dishes; wet them, gently massage them with liquid soap, rinse them, and pat dry (no rubbing) them with a piece of paper.
@Bacchanalia psh.. who's got time to take care of stuff when you could just have the more durable product to start with lol.
Ah but the trouble with glass lenses is they would break easier than plastic. Ever drop a pair of glasses with glass lenses on concrete?
@@shanetaylor761 I’d rather have to take better care of them than have my nose bridge ache each day from the weight. Do you know how heavy glass is?
I did, just last year, switch back to glass lenses. I just got frustrated with how easily plastic lenses get scratched.
Hank you and your brother are national treasures and you bless us with your knowledge so much
So damn true. Thank you, Hank and your brothers.
who is his brother?
I once went to the optician and they said I was short sighted in one eye and apparently that’s the ocular jackpot because I’d have one reading eye and one long distance eye but then I went back a few years later and they said the short sighted eye was back to normal and I was sad because I wouldn’t get to wear multiple monocles
I always have my optometrist order actual glass lenses for my glasses. I've worked in optics for decades, and glass is still more resistant to surface scratches and had better optical clarity.
I'm an optician in Michigan. We use Plastic, Polycarbonate, Trivex and Hi-Index primarily. They have different pros and cons but we avoid standard plastic as much as possible because they shatter. You good sir need a progressive lenses. Allows for a distance, intermediate and reading area in a single lens. It takes a week to retrain your brain to look through the focal points but something tells me you'll understand the mission lol
That's what I was about to say, Progressive lenses Hank! Polycarbonate user here because I am a woodworker and PC is better for impact.
Depends on the brain, I took longer than a week & still may remove my progressives on steep stairs.
@@syedam.graham5735 I would have them lower the progressive first to see if it helps. Maybe a compensated lens if your Rx and Doc ok it. You are right some people can't get it, but those are rare cases.
Only the first week I really didn't want to wear my progressive lenses.
Because it was so frustrating, not because I m not a progressive person.
I’m the same way, I have to take my glasses off to read close up. I’m a paramedic and take them off to start IVs now, too.
And yeah… makes me feel old too, Hank.
“Someone save me.” How about the person who gave you the Rx for those glasses you have on?😂
Mine are made of glass. Just bought them 3 months ago. I told the eye doc I wanted glass because the plastic always scratched with in a few months
My glasses are still glass. It really depends on who is making them, what the Perscription is, and what you requested as options.
I also suggest bifocals.
😂 he's sponsored
@@notinterested8452 it doesn’t state that on his channel. Even if he was sponsored erroneous or misrepresented statements would not be cool.
Glasses can be made out of a number of materials. Glass, plastic, or polycarbonate are few of the possibilities.
@@GaiusMarius65 anyone who hasn't yet upgraded to modern bifocals should do so because they're vastly superior to the previous generation
This is basically what I came here to say, get some varifocals or some bifocals Hank!
Yep I prefer glass, as it is more resilient to scratches, therefore easier to clean them too. Generally it feels they can take more general abuse. Only thing is they aren't allowed for some sports.
The worst part you don't ever think about untill you hear it out loud. People that need glasses (myself included) are required to pay money to utilize the full potential of one our most important senses. Your sight is like 60ish percent of your incoming information to your brain. It's the ultimate "pay to win at life". If you have good eyes just imagine for a few moments what it would feel like to be told you had to pay money to "open" your eyes. Or you had to pay money to be able to read, appreciate art, watch your loved ones faces smile or cry. So many things you don't realize are tied to sight and a decent percent of the population can not do those things for free. Guess I'm saying we need better vision care/insurance.
Well said.
You don't ever think about it because the benefits so obviously outweigh the cost.
hank which video you shoot first? this one or the transparent frogs from the sci channel? you're using the same clothing
I felt that “I am old” as I’m sitting her wearing my reading glasses! Although this is a bit unusual, I think - nearsighted people usually need reading glasses later in life than people who aren’t nearsighted. Or so they told me when they made me sign THREE separate acknowledgments when I had LASIK in my early 30’s. I turned 40 and BOOM, yep, can’t see close up anymore 🤷♀️ Whereas my mom still wears contacts and ended up needing readers at around 50.
Hope your doing well bro.
I feel you Hank, I hate wearing glasses, having to clean them, worrying about scratching them, worrying about them breaking, etc. They're a hassle!
Idk about you, Hank my man, but my glasses have been glass since I was 9 years old (when I got them)
Very interesting that yours are plastic though, I imagine they are way less expensive (our lenses are 20-50 Canadian dollars, depending on the prescription and design)
I never hear of anyone having glasses actually made of glass. And the reason is simple: safety. If you trip and fall on your face with glasses actually made of glass... Let's just say you won't be needing those glasses anymore.
@@mcgoldenblade4765 I've fallen on my face a fair few times with several different pairs of glasses, and they'll pop out of the frame before they would ever break. Not that a cracked peice of plastic would be less dangerous for your eyes... Bad either way. But I've seen glasses get run over by a car, and they are definetly glass, not plastic.
polycarbonate lenses are overwhelmingly the norm in most places. you can get glass, but only by special request. the main advantage to plastic is not safety, but weight. they weigh about half as much, but they also cost more. i went to Costco for mine and they were $65 US for just the lenses.
So you’re saying I’ve been wearing Plastics this entire time?!
Instead of bifocals, I think they now have glasses with a continuum of focus strength which varies from center to bottom.
Nah, they still do bifocals. My mom and sister both wear them. Sure, they can do continuum now, but bifocals are still a thing
They are called "progressive lenses". They have been around for more than 15 years now.
I have seen trifocal glasses too. Looks cool
Went to eye Dr on my bday last year just for him to tell me I need bifocals. I'm 36 🙃 I was offended and told him I wasnt ready for those 😂
If it makes you feel any better, I had to get bifocals last year. I'm 30.
My eye sight started going shit in my late teens. I believe genetics can play a role in it not just age.
Glasses are fantastic, especially the transitional lenses I have in. Been wearing them for almost 30 years now.
Good for u, that ur eyes didn't got worse in almost 30 yrs. Mine did change and in like almost 10 yrs I now have had to change them 3x and soon again pretty sure.
Don't know what ur talking about but that's a long transition
Glass is standard; I would have had to pay extra to get plastic ones. Since I'm cheap, I have nice and heavy glasses.
Depends on where you are buying them from. All the online places I looked at that do low and mid cost glasses only do Polycarbonate or other plastics. To get glass glasses with lined bifocals I have to go to my Optometrist and pay the big bucks.
What about contacts? Can you explain that, or is it the same concept?
Hank, you have so much patience. Thank you for patiently educating people with your channel. I would not be able to keep my cool explaining things as you do. Keep up the good work man.
I think an important point to make here is that glasses are made of plastic because we can make glasses with higher refractive indexes than glass has, which allows those lenses to be thinner and lighter than the equivalent lens made of glass.
You can still get glass in many countries. I regularly have a plastic and glass pair, the plastic scratches so its nice to have a pair that is crystal clear.
I also get actual glass lenses for the scratch resistance. They are thicker (and heavier) than plastic lenses, so it's a good thing my prescription is mild, so they're still fairly thin.
Could you imagine we called them “plastics”
at least here in Canada, you can order glasses with glass or "plastic" lenses.
glass is a bit more money, but the biggest thing is weight.
When light travels through a medium with a different optical density, it either bends towards or away from the normal. Gotta love Snell’s law
n sin i =n' sin i' AM I RIGHT!?
@@miabond5198 yup! Depending on the two mediums the light is going through, the angle of the light will bend either away or to the normal
So they should be called plastics instead?
What is Hank looking for out the window?
The only thing that irritates me about glasses is that we have to pay for them. I didn't make my eyes be bad on purpose, I was born this way, but now I have to pay to be able to see as clearly as someone with perfect vision.
You can actually scientifically blame your mother for her piss poor diet when she was pregnant with you!
but why should other people pay for YOUR bad eyesight ?
their eyes are probably fine.
Optometrists have to be able to make a living off their service. You can't expect every profession to provide you free shit just because you were dealt a bad hand at your birth.
No wonder they scratch so easily
I miss my glass glasses. Heavier, but super chemical resistant.
you can still get them you just have to pay more money and if its through insurance they will never pay more money its always the cheapest option
@@imchris5000 Not just more expensive, also hard to find. Not many companies make the blanks any more, and almost none of the major manufacturers work them. It's probably not impossible, but it's difficult.
People are out here seeing for free
Glass lenses are outdated and not the best option optically. Plastic (CR-39) with a premium anti-reflective coating (anti-reflective to reduce glare, improve visual clarity, and to add scratch resistance as well) is a good option for someone with a lower prescription.
Someone with low vision or only one functional eye may consider polycarbonate or trivex lenses as they are more durable and impact resistant (also paired with a premium anti-reflective coating). These lenses are not only thinner, but they provide even better visual clarity for someone with a more mild to moderate prescription.
Then there are your High Index type lenses (i.e. they have a high refraction index). These lenses are good for those with higher prescriptions (typically greater than a +/- 4.00) as they provide not only the best clarity, but they provide the thinnest possible lenses for people with higher prescriptions who would normally have thicker lenses.
For Hank's issue of not being able to see up close, it sounds like you need a multifocal (whether that be a lined bi-focal, lined tri-focal, progressive / aka no-line, or some sort of accommodation lens) - [this is not a diagnosis of any sort as I am not a licensed doctor of any kind, but rather this is a suggestion of what to talk with your optometrist about as it could be a possibility that you need a multifocal.. that is for you and your optometrist to discuss!]
I'd recommend seeing your optometrist to address the issues you are having as it may be something simple or even more complex.
Bro what are you looking at
It's also a part due to the curvature of the glasses. The refractive index (how much the material bends light) and the curvature of the lens works together
Actually, the most common material for glasses is either yes, plastic or poly carbonate, which is more Impact resistant, and better for kids and also lighter weight
Feel ya dude I’m 38 now..
But this isn’t so trippy because they scratch so damn easy!!
Hank's eyeglass lenses seem to be CR-39 (cheap plastic) with zero "up grades"; anti-glare, anti-scratch, etc... But them at Warby Parker; polycarbonate vs with anti-reflective and anti-scratch coatings included.
CR-39 has day plastic look to them.
The rest are made from polycarbonate, or high index "plastic".
Ok, burst bubble here. I'm older than you by 2 years, I believe. And for the last 6 eye Dr visits, I am pissing them off... so much so that I had to switch Dr's. Each time I've improved astigmatism gone, 4.50, 4.25, 4.00, 3.75, 3.50. In Dec I could have gone down to 3.25, but we decided to wait.
Also, I hobby without glasses: fiber arts (cross stitch, hand sow, and embroidery a little)
So they tell me I'm ananomaly.
In Ukraine we mostly use glass, but you can order plastic if you want. Glass is better.
Oh great so I didn't 500€ for glass that made my eyes relax (cause they're not looking in the same direction.. yey?) I SPEND 500€ ON PLASTIC and I already had the frame TwT
Ag least it doesn't break that fast(?)
Glasses are made of CR-39 or Polycarbonate which have refractive index of 1.49 and 1.55, higher refractive index means you can make thinner glasses and it can go as high as 1.8 but usually 1.67 and 1.74, hither gives thinner glasses but introduces chromatic abborations on pherifery.
Crown glass is still really common. Not the majority anymore, though, as CR-39 is practically equal or better than glass, but much lighter weight.
Glass is actually a really good option. It is the cheapest, and provides the best optical quality. The only real downside is weight.
I believe income shouldn't decide whether someone's child can see the world and thrive or not. If you buy a pair of prescription glasses, most of the cost is in the frame, not the blanks. So basically, you're paying €100+ for an expensive piece of cut sheet metal, or worse, plastic, while paying about €15 for the lens blanks.
(On that note, Hank, tell us why, and how the monopoly of a major company is responsible for low income families to not have access to adequate visual aids.)
To your “someone save me” ✋ don’t shoot the messenger here - but - stop eating chicken, you’re most likely allergic. Give up chicken, eggs, certain breads, certain pastas, cakes, anything made with eggs, etc. you’ll likely find within a year your eye sight will drastically improve. Again, ✋ don’t shoot the messenger, you did say “someone save me” so, 🤷🏻♀️ just sayin’
I had glasses made of glass when I was in grade school, into high school. Durable, high index optical plastics didn't yet exist in the 1960s and 1970s. Then in 1976, I got contacts (hard lenses only in those days), and wore glasses only before putting them in, and after taking them out. By the time I gave up contacts (2006) it was impossible to buy glasses made of glass; the only choice was regular plastic or high index (made the lenses thinner but had more chromatic aberration, for which the solution was smaller lenses).
As far as old, the best solutions I know of are bifocals, or two pairs of glasses (I use both -- single vision distance glasses, for driving and things like watching TV or movies in a theater, and bifocals with a computer prescription, because I do close work all day and regular bifocals won't focus close enough). Some folks get Lasik, with one eye for distance and the other for close-up (like reading), but I'll pass, thanks.
Your nicer more expensive sunglasses will have glass lenses them. Some people will have glass put into their daily pair as well, I have several.
Glass is an optically superior material, just expensive to manufacture, fragile in comparison to other materials, and harder to make thinner at higher prescriptions.
Each material DOES have its own index of refraction. Air has an index of refraction of 1.53. Plastic 1.59, then we have a material called high index plastic which has an index of refraction from 1.6-1.74 in the US, however you can get it at higher index and thinner materials in places like India and China due to regulations preventing us from accessing here.
If you have a small or average RX, you should consider lenses made from Trivex, as it has an index of refraction of 1.53, the same as air. It is impact resistant similar to polycarbonate but without the compromise optically.
- Former Optician
Thank God it's plastic. I'm SUPER farsighted, so my glasses are really thick. Only half as thick as they could be, though, since I use what's called high index lenses. Imagine how heavy they'd be if they were made out of glass. I'd need a neck brace just to hold my head up.
Again someone who failed basic Physics - 5th grade.stuff.
So, the right answer is: Nothing. That is why they work.
If, they would be opaque.
Unless you had very old weird glasses they are all plastic?? Really?? Why is it that that uptil 5 years ago I specifically had to tick the "plastic" option otherwise I would get glass instead? We are talking about an "average Joe" optometrist in town, not an obscure one. Fact is: every decent optometrist offers you the option to choose glass over plastic.
You're knowledgable for sure. But some subjects you're just assuming, based upon nothing other than your own thoughts
Mmmmm…plastic…
Several, HUNDREDS of dollars worth of…plastic…
Plastic= cheap, hard to break and lightweight. Cons: scratches! Dont last for long .
Glass= more expensive and heavier, breaks easily, pros: no scratches! Last very long.
Hank, you're smart, you know life expectancy only keeps going up. 42 is not old, not even middle aged yet, 42 is the new 22 😂. But also consider yourself lucky you don't need bifocals. Yet.