[hinkley]

These days, at least if you can afford designer, they use rare earth magnets and the frames are exactly the same shape.

Since most glasses only grind the back side of the lens, they fit pretty closely together.

Which is also why you wouldn't be able to reverse the position of the lenses without changing how they're ground (also thick lenses hidden behind the frame conceal just how bad your eyes are, which some people get self conscious about.

Point was, if you wear a pair of glasses that people require you to take off regularly, you still need to be able to see, and that means carrying two pair of glasses. Transitions lenses exist in large part because people can't be arsed to carry around two pair of glasses.

[smeej]

You're missing the point. Corrective lenses have thickness. For the frames that use magnets to add a sunglass layer, they only work because it can go on the outside, with the lens already set in the frame at the right distance from the eyes/lashes. It just wouldn't work in reverse, to take a sunglass lens at the right distance and snap something in behind it. You'd get oily lash streaks all over the corrective layer constantly.

It's even worse if you wear really thick glasses, because sometimes they even have to sit slightly proud of the frame in the front.

Your solution just isn't viable for this problem, as any longtime glasses wearer could easily tell you.

If that's not enough, there's a whole industry of people designing eyewear; you really think "What if you just added the corrective part inside the tinted part?" wouldn't have been done if it were viable?

[hinkley]

No man. Look.

Take a pair of glasses. Attach sunglasses to them. Move the bows from the glasses to the sunglasses. The geometry of the glasses or frames don’t matter, it’s whether there’s enough distance from the eye.

My glasses have almost always sat proud of the frames. And there’s plenty of distance behind them. (I’ve had sunglasses that brush my eyelashes though, when I was young and they were cheap, and that bugs the hell out of me).

> If that's not enough, there's a whole industry of people designing eyewear; you really think "What if you just added the corrective part inside the tinted part?" wouldn't have been done if it were viable?

First of all, that's an Appeal to Authority, and you know where you can stick that. Two, you think I'm trying to solve a very old problem, which means you missed the point.

Putting something on your face that vastly outsizes and outcosts your glasses is a brand new problem.

Scientists get eyepieces for microscopes with prescription lenses. That's not on your face. Skiers just buy goggles with prescription lenses, which cost almost as much as VR goggles. That's basically a luxury market, not a consumer market.

Also the whole fuckin' point is that none of these solutions (to people insisting you take your glasses off) work because a rounding error of people are going to carry two pair of glasses with them, and even the workaround is unwieldy. You're lost in the weeds talking about the physics of it, which aren't a problem and aren't the real problem.

[smeej]

What you actually said was: > Clip your prescription to a pair of sunglasses instead, or to your smart glasses.

You might have to clip them to the backside to get it all to work out.

And what does "Move the bows from the glasses to the sunglasses" even mean? Bows?

You can't take a glasses frame that is designed to be worn at a normal distance from the eye and then clip something to the back side of it, between the original lens and your eye. There's not enough space to add a corrective lens back there.

Even if there were, it's still unfeasible, because the part you have to take off is the smart part or the tinted part not the prescription part.

Never mind that it's only a rounding error of people who are willing to carry around a clip-on layer either, because it requires nearly as much protection as a full pair of glasses to avoid breaking it.

Making the prescription part the clipping part is inane on every level. Nothing about it works.