Eco-friendly sunglasses by Stella McCartney

Stella McCartney will launch a line of eco-friendly sunglasses made of more than 50 percent natural and renewable materials for Spring 2012.

"The greatest challenge was the amount of time that was spent on research and testing to get the best quality product possible with the highest performance in terms of resistance, while still maintaining the style and finish we always try to achieve," said McCartney.