Actually small sized frames are for people with small or narrow faces. They are specially designed to ease the selection of proper comfort and fashionable eyeglasses which won't prevail facial features of a wearer still reflecting style and individuality. There is a good choice of traditionally looking rectangle, square, round and other shapes of narrow glasses.
Meanwhile a couple of years ago fashion land welcomed micro glasses. That was the comeback of the retro trend and fashion-addicted folks were constantly spotted in this micro eyewear. From the point of functionality these minuscule glasses are very impractical - they even cover the smallest part of the eye. But they are not supposed to be practical like many other things which exist only for fun and amusement. The great diversity of teeny tiny glasses from the smallest cat-eyes and those of weird geometrical shape to the narrowest skinny glasses with extended rectangle lens. They are all a bizarre combo of fashion and futurism. And like many ultra fashionable things they are not concerned of utility. Their foremost target is to be cool, to rule out banality, to add fun and eccentricity. And it is of course not about protection of eyes or comfort reading. Micro eyeglasses are the small thingies which have a big impact on the appearance - no one will escape of the attention wearing this original accessory.