A brand that is environmentally conscious, has available clip-on sunglasses, and looks great? Look no further. ECO has a One for One model - every time someone buys a frame they plant a tree. ECO's eyeglasses are bio-based, made from 60% renewable oil. Although ECO is dedicated to protecting the environment, the quality of their eyeglasses are still great and very lightweight. The eyeglasses are perfect for those who don't want to carry around two pairs of eyeglasses.