UV radiation is part of the electromagnetic (light) spectrum that reaches the earth from the sun. Both UVA and UVB, however, penetrate the atmosphere and play an important role in conditions such as premature skin aging, eye damage (including cataracts), and skin cancers. Sunscreens are products combining several ingredients that help prevent the sun's ultraviolet (UV) radiation from reaching the skin. Two types of ultraviolet radiation, UVA and UVB, damage the skin and increase your risk of skin cancer, Tanning, Premature Aging, Sun Burns, Pigmentation etc.