Sunscreen is probably the best anti-aging defense available for your skin. This is because it protects the skin from the sun’s ultraviolet (invisible) rays that cause oxidative and DNA damage.
In addition to the visible light we get from the sun, we also get invisible rays UVA and UVB. UVA (think A for Aging) can penetrate deep into the skin and cause premature aging, sun spots, and hyperpigmentation. UVB (think B for Burn) is the invisible ray that causes sunburn and tends to damage the skin's more superficial layers, it also plays a key role in the formation of skin cancer cells.