This week we compare Rosie Huntington-Whiteley's city style with Kate Bosworth's sunny Coachella pool party look. Both beauties are wearing the trendy Westward Leaning sunglasses, also favored by celebs like Emily Blunt.

Rosie wears hers around L.A. with an all-black look and her hair pulled back in a tight pony. As usual, Kate's look is a little more laid back and cool with beachy hair and a black, sparkly shirt. Definitely two times a girl needs her sunnies - street side and pool side! Which look do you prefer?

It's hard to tell which pair of sunglasses each style setter is wearing, since the brand uses the same frame for every pair. The frames are made from Mazuchelli acetate with thicker acetate sheets than most sunglasses so they're weightier and more substantial. (Maybe also more resistant to sitting on them in the car? We can hope.) The difference is in the unique materials inlayed at the temple of each pair, each representing a different cause. Ten dollars of every sale goes towards causes like preserving National Parks, the rehabilitation of New Orleans or Native American craftsmen. The lenses are made of platic, which is more resistant to chips, scratches and shattering than glass. They are 100% UVA/UVB protective, but not polarized - so you can still read your smartphone or tablet comfortably while wearing them.

It's a really cool concept, and the brand swears their frames suit every face. They offer free returns and exchanges for the life of the glasses, so they really must believe it! At almost $300 the lifetime guarantee is nice to have.