Wearing sunglasses is one of my favourite hobbies. I have sensitive peepers anyway (something to do with contact lenses or something), but even if I didn't strictly NEED them, i would still "need" them. I just think they look make you look cooler, and me and my housemates have been known to have "sunglasses-mandatory" nights out. It's fun, everyone treats you like you're special.
My clothes are mostly neutral coloured and "simple" (boring), and if I'm wearing makeup, 90% of the time it will be a "five product face", but in my sunglasses choices I let my inner high-maintenance diva take over. The more extravagant and ridiculous, the better. But don't get it twisted, I still want my sunglasses to be cheap, because that way I can have an expansive wardrobe of different ridiculous touches to add to any outfit. Here are two pairs I got recently and am very pleased with (they are both from eBay and were about $10 each - eBay is the BEST PLACE for cheap and silly sunglasses).
The first pair are some Celine knockoffs. I hate to admit it but I do enjoy a fake designer sunglass - everything about my appearance from my poorly cut fringe to my extremely smashed phone screen suggests I have no money, so these make a nice contrast. I do sort of see that these are somewhat gaudy and horrible, but scruffed down with the rest of my appearance I just really like them.
The second pair are Miu Miu "cut out" knockoffs which are just so cool. They are slightly tamer than the Celine pair, and basically look like a classic, boring pair of sunglasses but with the bottoms cut off. (A classic with a twist? But what a horrible, overused phrase.) I favour a tortoiseshell frame because I think they look super great with an all black outfit (where black sunglasses look a bit teenage-emo).
Sunglasses are the easiest way to add a "bit of jazz". Seriously, all you have to do is put them on, and you're done. You have to wear some when the sun comes out, so why not have them be fun-glasses?