Experts say that the majority of premature fine lines are caused by excess sun exposure. Yet another reason to cover up before heading out. UV rays damage the skin's ability to produce collagen, which is scaffolding for the skin, providing it with firmness and structure. When collagen levels are depleted, the skin is prone to sagging and wrinkle formation. Your first line of defense is protection: always wear sunscreen before stepping outdoors. Your second step is repair: the right active ingredients can help restore structure and firmness to the skin.