No matter how gray the sky is outside, few self-respecting fashion people would ever leave the house without a proper pair of sunnies to accompany their outfit. After all, Anna Wintour never goes anywhere without hers. It's not so much a matter of actually shielding your eyes from the sun, but about adding a feeling of completeness to a look. A pair of sunglasses can add instant impact to an outfit as simple as jeans and a t-shirt without any measurable effort on the part of the wearer.