The leading cause of preventable skin damage is ultraviolet radiation. However, two people with different types of skin will have different results from the same degree of sun exposure. Fair skinned, blue eyed people (Fitzpatrick Skin Type 1) have skin that evolved to live in Europe and places without significant ultraviolet exposure. Darker skin with more melanin (Fitzpatrick Type 6) is better adapted to sun exposure and designed for tropical latitudes. These differences in pigmentation translate to requirements for high SPF for people with fair skin and lower SPF for those with darker skin. The requirement for differing degrees of protection depending on skin type is the main fault with skincare moisturizers that include SPF 15 and are marketed as “daily wear.” They are not adequate for the daily activities of most of the people who purchase them. For instance, skin that needs SPF 50 will burn with only an SPF 15 on.
Sun protection is necessary regarding the ultraviolet light does to the skin. Ultraviolet light interacts with the skin by radiating it. Different types of ultraviolet light penetrate to different levels and have interactions with molecules and cells. One significant interaction is with the DNA of the skin. As DNA is affected by sunlight, it is altered and the information contained in the DNA is changed. Most of the time, the damage can be repaired but as we get older our ability to repair DNA decreases and mistakes begin to accumulate. As this occurs, faulty genetic information is translated into defective proteins and abnormalities in the cells are seen. Abnormalities including skin cancer may result from the damage. Ultraviolet radiation also damages collagen and this is seen on the surface as wrinkles. Liver spots are also seen following exposure to sunlight as the body tries to shield itself.