This is a pretty good summary of traditional glasses frame materials, to which I will add the following unconventional materials used in 3D-printed frames, that I have personally tried to wear quite extensively:
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PLA: lightweight, cheap, forgiving, ubiquitous, reasonably solid and durable, VERY easy to form - and deform - under moderate heat. Don’t leave PLA frames on the dash of your car in the summer or you’ll come back to a gooey mess. You can easily chemically-polish PLA smooth with acetone to make PLA frames very comfortable to wear on your skin for extended periods of time. PLA is a bioplastic made from plant material and is biodegradable, so it’s a good choice if you’re environmentally-minded. PLA has very low toxicity and is regarded as food-safe.
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PETG: a variant of PET - think frames made of the same plastic soda bottles are made of. Slightly stronger than PLA and a bit more tolerant of heat, but harder to polish smooth. Like soda bottles, it’s not terribly environmentally friendly, but glasses frames use very little of it. PETG is also very low toxicity.Very comfortable to wear for a long time if you take the time to polish it.
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PVB: visually stunning. Can be polished to a shiny sheen in seconds - and destroyed just as quickly if you overdo it - with IPA. Clear natural PVB can be made almost transparent! Not that great mechanically, so only use it if you never abuse your glasses and you’re after the aesthetics. Quite comfortable.
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Wood-plastic composite: I’ve only tried wood-infused PLA. It’s substantially weaker than straight PLA and it’s not terribly comfortable to wear for more than 12 hours, but it looks stunninly like real wood with a modicum of sanding with 400-grid sandpaper. If you like wooden items, this one is for you.
I’ll never get glasses made with that Flexon/memory metal again. Although they really are lightweight and rather flexible, the last two pairs of them got brittle and snapped right in the center of the nose bridge in almost a year.
The second pair that did this managed to snap in half while I was simply cleaning my glasses, no undue stress or anything like that.
Now maybe if they made the nose bridge thicker, and possibly of a different stronger rigid metal, they might be alright and last the long haul, but honestly I think they deliberately engineer them the way they do as a known weak point.
Planned obsolescence…
That sucks. I bet you paid premium for the fancy material too.
Do you remember the brand name?
I’ll have to try to see later after I get home, I don’t think the markings on them are totally worn off yet. I loosely rember it says “Gun Metal” on the left earpiece, not sure if that’s the brand or not.
I did manage to rig them back up though, using a piece of a hairpin, 3 layers of heatshrink, and a few wraps of tie wire at the ends to hold the hairpin tightly in place.
The rigup totally works too, but over time sweat starts degrading the heatshrink and it starts swelling up. Thankfully I have other glasses now, so the rigged up ones are put aside as backups.
I’ll see about posting those later on.
Actually silly me, I just looked it up and Flexon is the brand. It’s a Marchon subsidiary. Flexon specializes in NiTiNOL frames.
Not being Luxottica, presumably it’s not a crap brand. And NiTiNOL isn’t exactly known to be prone to early fatigue failure - kind of by the nature of the stuff. So maybe it’s a weak design, or you got exceptionally unlucky.
Well, if it counts for anything, both sets of frames were exactly the same model, from Walmart. Luckily I got the second set under warranty just 2 weeks before the warranty expired. Not so luckily the second set broke exactly the same way, almost a year later.
The nose bridge was on the rather thin side if you ask me. Honestly I don’t see why they even chose to use that metal in the nose bridge, that’s a high stress point. As long as the earpieces are made of the stuff, it’s all good to me, if they could just be made to last.
From my understanding, even as flexible as that NiTiNOL stuff is, over time it gradually weakens the molecular structure after so many times flexing.
Honestly I don’t see why they even chose to use that metal in the nose bridge, that’s a high stress point.
Not only that, but you actually don’t want the nose bridge to flex. Your lenses are cut to work at a certain angle from one another and at a certain angle from vertical, set by the frame’s geometry. If your frame flexes - typically for example if your temples are too narrow and the hinges aren’t spring-loaded - then the lenses will “point” inward and your correction will be incorrect, potentially giving you blurry vision or headaches.
I think the whole flex thing is kind of a marketing gimmick: you’re sold on the idea that you can sit on your glasses without consequences - a promise I’ve never seen materialize - and the compromises needed to achieve that make frames that easily become optically unsuitable.
Walmart
That might be the quality problem. Wallyworld isn’t exactly high-end stuff.
The first pair, I’d actually sorta ‘play’ with them at times, flexing the nose bridge upwards of around 90⁰ sometimes. The whole time I thought it was neat as hell, but also simultaneously thinking “How long will this stuff really last”
If anything, I wanted them to break while still under warranty, and luckily I got exactly what I wanted, almost exactly 2 weeks before the warranty expired.
After getting the warranty replacement frames, I made a point to not deliberately flex the nose bridge, no more than it would naturally flex while wearing them. And honestly, the nose bridge didn’t flex very much naturally, the earpieces plus the hinge springs did like 95% of the flexing. They were very comfortable actually.
But alas, even while treating the replacement frames with much more care, they still managed to break in the same exact spot. ☹️
I’m back home now, the frames are labeled as M•Flex, I assume that’s the brand name. ME507 GUN 53[]19 145 (the brackets represent the square, I assume those numbers represent the exact model and dimensions).
53-19-145 are the standardized frame measurements. They mean:
- Eye size: 53mm (that’s the width of the lenses)
- Bridge size: 19mm (that’s the width of the space for your nose to fit in)
- Temple length: 145mm (that’s the length of the temples from the hinge to the tip - only valid for library or skull temples, but not for cable temples)
I assume ME507 is the Flexon model number and GUN is the color of the anodization (i.e. “gunmetal”)
As someone who buys at least two pairs of glasses a year and is very into 3D printing this is very relent to my interests. Thank you.
It would be great to see some close-up pictures of frames you guys have printed for yourself.
Sure. Here’s a video showing the progressives I wear most of the time - printed in Galaxy Black PETG:
Here’s the same design in green PLA, with near lenses mounted (I use those at home to read because they’re really fugly 🙂):
And here’s a version printed in TPU:
I tried to create unbreakable frames. They’re unbreakable alright, but also much too soft to function properly as glasses, sadly.
And finally, here’s a different style frame I made for a friend whose acetate frames crumbled to dust with time for some reason (probably a manufacting defect of the plastic material) who wanted to salvage his lenses:
It was a quick test print I sent him a picture of to ask him if the shape was okay. The final print was much smoother. I don’t normally take pictures of the frames I made, but I had this one lying around in my cellphone, so there ya go.
I love the last one. I have a somewhat related problem with my frames, in that the paint is starting to peel away in some spots (probably due to my oily skin ^^') but the lenses are still perfectly fine. I’ve tried to find the same frame online but it’s sold out everywhere, so maybe I could replace it this way. After all a good 3D printer is barely more expensive than new frames and lenses these days !
That’s the reason why I started making my own frames. The whole new frame ⇒ new prescription ⇒ new lenses ⇒ new fitting, and the fact that frames never stay on the market for very long, is very much by design. And I don’t much like feeling swindled.
Athough, in fairness, even if you do find the exact same frames, no frames are exactly alike. So it’s quite possible that your old lenses wouldn’t quite fit - particularly snap-in lenses. So to the eyewear industry’s credit, there is an element of non-interchangeability with certain frame designs. But frames with screw-rims and wire rims are definitely interchangeable, and clearly it’s in nobody’s commercial interest to let you find replacements for those.
But the real clincher for me was this: it takes weeks to get new glasses. When I need new glasses, I need them right now, not in five weeks.
Making your own frames, provided you have the lenses, makes you totally self-reliant. You need them, you make the same day - the same hour even with 3D printing. What’s more, with 3D printing, It’s trivially easy to adjust the frames to the existing lenses: just change a dimension or two, re-print, and hey-presto, 15 minutes later, you can try the lenses for fit again. And once you have the correct dimensions, you can just re-print those over and over as you routinely break the frames - because hey, you don’t really have to be careful anymore 🙂
You do need to invest the time to learn a CAD program to model the frames if you want to reuse your existing lenses. Or you can go with an existing design someone else made and order a set of lenses for those - not cheap, but they’ll be your last pair of lenses until your prescription changes. Then after that, like you said, a good basic printer is very affordable these days and will pay for itself the first time you need to replace your frames.
frames never stay on the market for very long
One thing about that: I don’t know if this is still valid, but back in the late 90’s / early 00’s, I used to order super-cheap, super-solid - and super bland - frames from French distributor Alain Afflelou that were sold only on the French market (so I’d get friends in France fo buy them for me.)
France has (had?) a cap on the amount paid out by social security on frames, and all opticians in France carry (carried?) something locally called “montures secu” - lit. “social security frames” that were, well, let’s not mince words, designed for the poor with price and durability in mind.
Opticians in France try (tried?) really hard to steer their customers away from the “montures secu”, strongly hinting that if you chose them, you’d look like a poor person. But the truth is, those frames were properly solid, super-cheap and they’re still made today and referenced as standard designs in almost all edging machines.
The last Alain Afflelou pairs I bought some 20 years ago were like 15 euros a pop (I bought a whole bunch of them) and they’re properly indestructible. I still use them on occasions, and when I need new lenses for them, I show them to my optician who’s nowhere near France and they have this Alain Afflelou frame model in their database. Amazing!
So if you don’t want to go the 3D-printing route, that’s maybe something worth pursuing. But like I said, I don’t know if the “montures secu” are still a thing in France.
