Sun exposure causes most of the skin changes that we think are a normal part of aging. Over time, the sun's ultraviolet (UV) light damages the fibers in the skin called elastin. When these fibers break down, the skin begins to sag, stretch and lose its ability to go back into place after stretching. The skin also bruises and tears more easily—longer to heal. So while sun damage to the skin may not be apparent when you're young, it will definitely show later in life.
Exposure to the sun causes: