Your only option is insurance. You're not gonna find an all-steel pair (would be terribly uncomfortable) with somehow unscratchable lenses, and short of that, how could any pair be bifl.

Honestly, if they have flexible or generally solid hinges, that's the most you can do to avoid the most common point of failure in cheap glasses, and beyond that, their longevity depends on use much more than build quality.

As for sustainability, there are a lot of cheap and nice brands using recycled materials or bamboo. But the best thing you can do is treat a pair well so you can go longer before replacing them.

Gatorz are tough as hell, and have some of the best polarized optics I've ever worn.

They'll do lens replacements, and can make prescriptions as well.

Careful leaving them on a car dashboard though. They're aluminum frames and I burned my temples once.

I have been wearing the same pair of Revos for 10ish years. Prior to that it was RayBan Aviators for ~10 years that I had until they mysteriously disappeared. Got to say I really like the Revos but they are getting a bit scratched up.

Can’t say that I know enough about manufacturers to recommend one that uses sustainable methods but am interested to hear what comes of this thread.

Do you have a Costco membership? You can order regular sunglasses online or in store at their optical department. I recently went with them for 2 pairs of prescription, 1 regular glasses with transition and 1 pair of prescription sunglasses. Total before insurance reimbursement was less than $300. You should be able to get a nice high end, high quality pair of non prescription sunglasses for less than $200 and they stand behind their products way more than other merchants.

Be aware that their online store is extremely lacking and it's probably better to go in store unless something online works for you.

I preach the holy site that is Costco to anyone who will listen. $60/year can save you hundreds from optical and pharmacy alone.

Non polarized Serengeti Drivers. Come in different frame styles. Best lenses I have ever used.

I recommend Maui Jim. The lenses are better than all others and I’ve had a pair that I use daily since 2013. I did eventually replace the lenses about 2 years ago; their service department will do that for $100, and turn them back good as new. GL