Although sunlight accelerates the aging changes in the skin, it has effects which are unique. Sunlight damage is most marked in those with fair skin and blue eyes. Blonds and redheads are especially vulnerable. Studies show that Caucasians who move to sunny areas are at a much higher risk of skin damage from sunlight. This often leads to skin cancer.
Unlike aging which tends to thin the skin, sunlight thickens the outer layer or epidermis. The elastic fibers are damaged, and premalignant and malignant cells may appear. Probably the most worrying aspect of exposure to sunlight is the marked increase in skin cancer.
The most harmful element of sunlight is ultraviolet radiation (UV). There are three types or bands of UV radiation. UVA(320-400 nm) does not have a clear role in skin damage although many authorities feel that it can be as harmful as UVB . UVB (290-320 nm) is the band width we usually associate with sunburn and skin cancer. UVC (200-290 nm) seems to be filtered by the ozone in the atmosphere and although at its role in skin damage is unclear, we may see more of its effects if the ozone layer diminishes. What all this means is that to look younger, and to reduce the risks of skin cancer, you should make it a daily habit to use sunscreen. There is even some evidence that prematurely aged skin can be improved by the regular use of sunscreens. Although there are many methods to resurface sun damaged skin, the best treatment is prevention.