I couldn’t tell ya 🤷🏾♂️ it’s entirely possible that the risk of the lenses splitting was exaggerated to justify their requirement of buying the more expensive lenses with the half frames.
Unrelated, but when I was buying my glasses, I’d fallen in love with these half frames, but disappointedly told the tech I’d have to pick a different pair when she told me about the increased expense. (It wasn’t that much more, relatively speaking, but I already couldn’t afford the glasses, and had explained earlier that I was trying to do things as cheaply as possible). When she saw how upset I was over not being able to get the frames I really liked over an ultimately negligible amount of money, she gave me the glass lenses for the plastic lense price.
Someone post the comic about people learning something for the first time.