When you see it once, it's just someone being eccentric – or else they're having some kind of bad day, maybe. When you see it twice, on the same block, it's two schoolgirls trying to make a statement. When you see it a third time, down at Suwon Station, maybe it's a peculiar local trend. But when you see it a fourth and fifth time, on the subway around Seoul, you realize it's an all-out fashion movement.
What's this, I'm seeing? Women wearing heavy-framed plastic eyeglasses, generally high-end designer frames like Ray-Ban or DKNY, without lenses. Personally, I think it looks cool, but it does strike me as a bit out there, as a fashion statement. Most of the few comments out in the interwebs that I could find are overwhelmingly negative, attributing the behavior to "emo posers" and the like. But… whatever.