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 🙂
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