It holds the glasses by the edge of the frames, so the lenses are suspended above the bottom of the case without touching anything and no padding material is necessary to prevent scratching.
And being specially sized for those glasses, the case is no larger than it needs to be.
They're prescription glasses. They're my regular glasses I wear every day. I made the frames but I can't print optical lenses, sadly. I wish I could because they cost a fortune and they're a real rip-off...
That's kind of my problem: my correction is not simple. I can get near or far lenses with my correction for relatively cheap - like $100 a pair. But progressives are eye-wateringly expensive.
As for my frames, they're both free and priceless to me because I make them myself. And just because they're not off the shelf, they're more rewarding to wear.