Mine are plastic, been wearing specs since I was 14 (I'm 52) and for the last 8 yrs, had Stepper frames (one of the lightest). My current frames weigh in at 5g but my lenses knock the total weight up to 16g. I need to replace but I can't get a pair I like and though these frames are available, the colour isn't (brown), I've had the blue, but I don't want them again and the other 2 colours aren't for me. I have transitions xtra adaptive which means they can only thin them down to 1.66 (is it?). I can't manage with clear lenses due to sensitive eyes (since I was 34).
I envy ANYONE who can go straight into a pair of frames, if I did that I'd be crosseyed due to my wonky ears that I NEVER knew about until I needed glasses. Getting them squared up can be difficult as I also have one eye brow slightly higher and the lady who fit them would always line them up with my eyebrows rather than my eyes. She said they were straight, I would say they weren't, battle of wills basically, now they listen! Besides, when I'm having to fork out around £400 for a pair of specs, I want the damn things to be comfy and look right!