Nothing adds that touch of old-school chic to an outfit quite like  a pair of classic cat's-eye sunglasses. Whether the angle of the upturned frame is extreme or somewhat subdued, this retro-influenced style is hands-down all the rage and was all over the season's runways. Want to get really bold? Instead of playing it safe with black or tortoise,  try a pair in white, or daring shades of red, yellow and pink. They're truly the cat's meow. --rpuccia 1.  Marc Jacobs 319/S, $188 2   Prada PR 19MS, $141 3.  Missoni MI671, $167 4.  Kate Spade VENESSA/S, $122