Skin protection. Ultraviolet (UV) light photograph of a woman's face with sun protection lotion applied to her left side (right as viewed). This image was taken by a digital camera adapted to filter through and detect only UV light. The left half of the face (dark blue) is able to absorb most of the UV radiation. The right half of her face, her neck and throat are unprotected (magenta) apart from the letters 'UV' inscribed on her cheek. Ultraviolet radiation in sunlight destroys cells in the skin's outer layer and damages tiny blood vessels beneath, causing sunburn. Repeated exposure can age the skin prematurely and increases the risk of skin cancer.