[Ao7bei3s]

More expensive lenses get you:

* A material with a higher refractive index (-> thinner glasses) and higher Abbe number (-> less dispersion). Scroll down to the "Optical Glass Selection" in this article for a diagram: https://www.edmundoptics.com/knowledge-center/application-no... - the stronger the prescription, the more it matters, but generally the step up from the cheapest material is much more significant than from the mid priced tier to high priced tier.

* Coatings (anti reflective, anti scratch / oil / water, and for sunglasses also: polarizating, and the tint itself of course, ...). These are all worth it in my opinion. I cannot praise the polarizing coating on sunglasses enough. And the anti reflective coating. "Computer vision" coatings are not useful in my opinion. Mirror coatings for sunglasses are a personal/aestetic choice.

* Glasses for people with astigmatism or with both near and far prescriptions are more expensive.

More expensive frames get you:

* Lighter, thinner frames and frameless options.

* Hinges that open a bit more than 90deg and flex back with a spring, so the temples will adapt to the head better. Better hinge materials (e.g. I've had hinges wear out).

* Titanium or memory metals instead of plastic of aluminum.

* "Aesthetics" and minor add-ons like laser engraving.

Obviously price only correlates with quality, paying more doesn't guarantee getting more.

[delfinom]

With lenses, yes, higher refractive index, coatings and the like drive up the price. The features are worth it, but some brands have massive margins on what is essentially the same highly automated processes.

>* Lighter, thinner frames and frameless options.

Your average person is not going to feel the extra 5g from a "cheaper frame". Most expensive frames are also hilariously cheap to make at the same factory.

>* Hinges that open a bit more than 90deg and flex back with a spring, so the temples will adapt to the head better. Better hinge materials (e.g. I've had hinges wear out).

That is buying undersized glasses. The "expensive frames" are just tailoring to people in denial of their head size. Though the other problem is, it's cheaper for a brand to make more of the same undersized frame, and add a spring hinge instead of offering frame designs in two sizes. Economy of scale for stamped process frames.

> * Titanium or memory metals instead of plastic of aluminum.

True titanium is a difficult metal to work with. The "Titanium frames" are largely a scam of some titanium alloy because it's actually usable to manufacture in such small frames. The end result is those frames break all the same.

The biggest problem is titanium work hardens. It is a strong metal but it essentially fatigues and snaps like copper. Make it thin like for glass frames and you allow it to start flexing and work hardening over time. Other applications of titanium don't make the metal thin enough to allow that to happen.

>* "Aesthetics" and minor add-ons like laser engraving.

Yea you pay for the "design". Laser engraving addons are sometimes available for cheap frames tho.

[ce4]

Yep, seconded.

Some more anecdata: The lenses' coating from my cheap unbranded glasses (plastic lenses) have begun to disintegrate/separate from the glass. My other glasses' Zeiss lenses are fine still (both being 8 and 6 years old).

Other than that, to the OP: get what you like, if you need the super thin lenses (depends on your level of myopia), go with the expensive stuff, else the cheaper lenses will also work. The more expensive coatings will filter more reflections, do you need a polarizing screen (doesn't work well with LCDs though)?. Then there's the lens material: glass (more scratch resistant) vs plastic (safer, because shatterproof). If you need two zoned lenses thats also different, and way more expensive.

Edit: oh and make sure that the eye distance is properly measured (i.e. at all), that is to make sure that the optical center is ligning up with your eye

[moooo99]

> if you need the super thin lenses (depends on your level of myopia), go with the expensive stuff, else the cheaper lenses will also work.

This also depends on the frame OP wants to go for. With thicker frames, thicker glasses tend to be less of an aesthetic issue than with very light, transparent of frameless designs.

[loceng]

Is this your field or you just became a bit of an expert through frustration?

[Ao7bei3s]

Thank you for asking, it brightened up my day.

I am not an expert.

A mix of interest, a compulsion/obsession with learning the basics of anything to make optimal decisons, and get taken more seriously by experts (it turns out all it takes to get your optometrist to take you seriously is to use words like "autorefractor" and "phoroptor"), overconfidence ("I know RF, and light is an electromagnetic wave too, how different can it be?") and I guess also frustration (what do you mean, I need to renew the contact lens prescription every year, I can only be prescribed one type and I need your blessing to try 2-weeklies from the same brand, which you would have happily prescribed instead of the dailies? No thanks, I'll just import them then.)

But really, I've just worn glasses for a long time and nothing I wrote there is actually all that deep. I may have read a few papers.