This is a pretty good summary of traditional glasses frame materials, to which I will add the following unconventional materials used in 3D-printed frames, that I have personally tried to wear quite extensively:

• PLA: lightweight, cheap, forgiving, ubiquitous, reasonably solid and durable, VERY easy to form - and deform - under moderate heat. Don’t leave PLA frames on the dash of your car in the summer or you’ll come back to a gooey mess. You can easily chemically-polish PLA smooth with acetone to make PLA frames very comfortable to wear on your skin for extended periods of time. PLA is a bioplastic made from plant material and is biodegradable, so it’s a good choice if you’re environmentally-minded. PLA has very low toxicity and is regarded as food-safe.

• PETG: a variant of PET - think frames made of the same plastic soda bottles are made of. Slightly stronger than PLA and a bit more tolerant of heat, but harder to polish smooth. Like soda bottles, it’s not terribly environmentally friendly, but glasses frames use very little of it. PETG is also very low toxicity.Very comfortable to wear for a long time if you take the time to polish it.

• PVB: visually stunning. Can be polished to a shiny sheen in seconds - and destroyed just as quickly if you overdo it - with IPA. Clear natural PVB can be made almost transparent! Not that great mechanically, so only use it if you never abuse your glasses and you’re after the aesthetics. Quite comfortable.

• Wood-plastic composite: I’ve only tried wood-infused PLA. It’s substantially weaker than straight PLA and it’s not terribly comfortable to wear for more than 12 hours, but it looks stunninly like real wood with a modicum of sanding with 400-grid sandpaper. If you like wooden items, this one is for you.