Oxidative stress is caused by free radicals that damage healthy cells. Free radicals are oxygen molecules that are intrinsically unstable because an electron is missing from their chemical structure. In order to achieve stability, they take an electron from the next available stable molecule (e.g. of a skin cell). A chain reaction forms, which can lead to an excess of free radicals and visible effects on the skin. With the passing of time, the skin looks old and rough, has pigment spots, wrinkles and bags appearing under the eyes if the body`s own protection system does not have sufficient antioxidants.