There's always something in fashion that someone is going to think is ridiculous and that others are going to follow regardless. It's about personal taste - and for a lot of young women - mimicking the style of their favorite celeb.
For what I can make out - a lot of people who wear them, apart from copying style, like them because they allow you to have off days with make-up - where most of your face is covered.
They accommodate for full shielding of the eyes - so if you're sat on the beach, reading a book you don't get ray above or below the glasses.
And a lot of people have said they're more comfortable.
I don't know if I agree with that - but each to their own.
A lot of people however, tend not to take their face shape into consideration when buying sunglasses and a slight alteration in the frame can change the style from looking 'weird' to something quite flattering and chic. Some face shapes should just avoid them.
That said - I much prefer a lot of other style sunglasses above this one.
I wear big glasses 'cause each one of my eyeballs is 4 inches wide. You may be wonderin if I have a giant head, whereas my eyes are so big, but nope, just about the size of a big cabbage, like everyone elses. The big eyes I was born with, but my ears didn't start growing real giant-like til I was 12. Got so big I finally had to snip em off, cause they were making my head too heavy. 'Course then my glasses wouldn't stay on so I had to jammer some plugs into my head. That hurt some. Like I always say, it's always rainin sumwhere.
I'm not into sunglasses in general myself lol, but I don't think it's that bad of a trend. Like most other trends, sometimes it looks good and sometimes it just doesn't. But people just do it because it's popular.
And, a fun fact that may be relevant: big eyes are one of the universal views of beauty, along with being symmetrical and whatnot.
I love both of those sunglasses but I'd only wear the second ones. I loveee big sunglasses! The bigger the better-they cover the whole eye area, you don't need to wear any make-up and you can just throw them on and they make you look great! I'm a big fan lol. And I like them to be totally blacked out so I can people watch lol.