Our defense against solar ultraviolet (UV) damage to skin comprises endogenous mechanisms of DNA repair and pigmentation, and exogenous application of light-absorbing and reflecting sunscreens. Our most important endogenous defense, DNA repair, has been the focus of molecular and clinical research, and recent advances are summarized here. The approach of using microbial DNA repair enzymes to augment the natural DNA repair capacity of skin has gained acceptance in many commercial products, and clinical studies have supported their benefits.