2w ago

Extensive skin contact with PLA and PETG seems okay

As you may know, I now wear 3D-printed glasses.

I've been wearing glasses for decades, since age 3, and because I'm lazy, I never take off my glasses even when I sleep, I'm not sure how, but even when I'm asleep, I never turn into a position that would damage my glasses. Decades of habit I guess...

Anyhow, the point is, apart from when I shower and when I go to the swimming pool, those 3D-printed glasses are sitting squarely on my face all day, every day. So probably close to 23.5 hours a day.

And I'm happy to report, PLA and PETG seem to have zero effects on my skin. No rash, no redness, no itching, zero discomfort. I've worn each material for at least 2 months straight and they seem perfectly fine.

I don't see any degradation of either material either, even after being exposed to acidity and oil from my skin for hours on end. I didn't expect PETG to react to anything, since it's more or less the same stuff soda bottles are made of, but I thought maybe PLA would degrade. But it doesn't. Perhaps it degrades slower than I anticipated. I'll report back in a year 🙂

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You wear your glasses to bed...?
- Dreams would be blurry otherwise no?
- Not on purpose 🙂 Either I fall asleep with them on, or I forget I'm wearing them. When I wake up, there're still there and completely unscathed. It's been like that for decades, so I don't sweat it.

Fascinating! Where do you order the lenses? I'm in the US and I can't find a place that is cheaper then Zenni where I can get my lenses and frames for <$20.
- I order my lenses from my local optician. They're not cheap - I pay $75 for single vision lenses and $600 for my progressives. But I have strict requirements for the material the lenses are made of (Trivex) and the el-cheapo Chinese suppliers don't really tell you what material they use (usually CR-39) or they simply disregard what you tell them.
  Also, I want the lenses edged with a precise kind of bevel and fitting the frame template I supply, and frankly the only company I really trust to do my lenses well is Hoya. They've always done a perfect job of all my lenses. Unfortunately, I can't order direct from Hoya. So I go through my optician and tell them what to tell Hoya essentially.
  But the point is this: however much my lenses cost me, when I need new glasses, I can simply print new frames. The lenses are a one-off purchase: if I break my frames, I'm my own man: I print new frames in minutes and it's like the accident never happened. I only replace the lenses when my vision changes, which isn't that often.
  Simply not having to have new lenses made each time you have an accident with your glasses makes 3D-printing the frames worthwhile, even if you splurge on the lenses.
  
  Zenni does trivex at a premium when compared to CR39. Still might be cheaper than $600.
  
  How do your lenses not get scratched? I usually have to replace the lenses before the frame

PLA is more resistant to degradation than it often has a reputation for. So yeah, it can holdup pretty well in a lot of use cases. For most, PLA frames would probably hold up just fine until they needed a new prescription. The issue with either common consumer PLA or PETG, is you can't be sure of just how anyone person will react to the constant contact with the material over time. Allergies can popup with continuous exposure. As always:YMMV

How'd you get the hinges to be strong enough?
- They're plenty strong, thin though they are. If you account for the shortcomings of 3D-printed parts in your design, you can make them quite strong without adding that much bulk.
  But mostly the thing that protects glasses in this style is that they're quite narrow, so the temples are almost flush with your head along the entire length. So even if you lay your head on a pillow, or you get hit from the side, it won't break your glasses. Before wearing those 3D-printed frames, I used to wear the exact same ones made of metal and I never broke them either solely for that reason, despite being rather active.
  Vintage style round frames are a lot more durable than more modern, more stylish wider frames. The cost of course is looking like you're a time traveler from 1910 🙂
  
  Dude you already need glasses so do something good for your eyes and seal the whole thing in epoxy resin or something. It's certainly not good for your health to get microparticles in your eyes and mucous membranes all the time... If it breaks (e.g. because you have an unfortunate fall or someone accidentally knocks the door in front of your head), there should also be fewer fragments that could pose a risk to the eye if it is sealed. Eyesight is too precious and it doesn't take much more work, although that wouldn't be an argument against it anyway, as health should have a higher priority.
  Otherwise I can only say: good work. A good printer owner who makes something really useful with the tool.

Longest I can wear glasses is a few hours before they drive me crazy and I have to take them off.
Were you able to make something more comfortable by having a custom frame that fits your face perfectly?
- Were you able to make something more comfortable by having a custom frame that fits your face perfectly?
  Yes that's exactly it. Although I didn't start with the 3D-printed glasses: I made my first frames myself some 20 years ago. It took me a bit of trial and error to get the shape of the nose bridge to match my nose exactly, and the ear hooks to match the shape of my ears exactly also. When everything was dialed in just right, the glasses pretty much "vanished" completely, if that makes sense.
  I did the same thing with the 3D-printed glasses. That's why I shared how to modify the dimensions on my Github, and if you go through the repo's history, you will find a few of the adjustments I did to get them to fit me perfectly. They have all but vanished too, and the very light weight of the 3D printing plastics make them even more comfortable: my current pair weighs around 11g.
  
  Is there any magic way to 3D scan a face to eliminate the trial and error?

Thanks. This is useful knowledge 👍👍 As for the fumes I still breathe in ... 😬
- Never been too concerned with fumes at typical temperatures (higher temperatures required for PETG and the effect of those temps on PTFE bowdern tubes are a different box of frogs), but stringing getting pulled into the extruder fans scares the crap out of me as it basically becomes an ultra fine dust that builds up in the air and eventually settles waiting to be disturbed.

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