Invisible and imperceptible radtion to the humans senses was discovered by the German physicist Johann Wilhelm Ritter, these are ultraviolet. Today this electromagnetic radiation is very important. We are daily exposed to the utraviolet because they constitute about 4% of the solar radiation. Many researchers have shown the harmful effects of radiation on the skin, butwe do not yet know all its danger. They are also responsible for tanning and emissions from both natural and artificialsources. It is therefore essential to protect our body against this radiation which we do not know everything. But these radiations are also used in the medical field with beneficial properties on the body, including the skin.
   We, Thomas Beguin, Adrien Ciret, Sixtine Descours and Ondine Deyrieux, are going to try to understand how to combine sunshine and health of our skin.