Sun exposure is one of the leading causes of premature aging and skin damage. Wearing sunscreen daily protects your skin from harmful UV rays that cause wrinkles, dark spots, and increase the risk of skin cancer. Even on cloudy days or indoors near windows, UV rays can affect your skin. Choose a broad-spectrum sunscreen with at least SPF 30, and reapply every two hours when outside. Pair sunscreen with hats and protective clothing for the best defense.