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photoreactivation pho·to·re·ac·ti·va·tion (fō'tō-rē-āk'tə-vā'shən)
The activation by light of something previously inactive or inactivated.
restoration to the normal state, by the action of visible light, of the deoxyribonucleic acid composing the hereditary material in animal skin cells and plant epidermal cells damaged by exposure to ultraviolet light. The phenomenon is also called photoreactivation, especially in microorganisms. The failure of cells to repair such damage, in individuals with certain biochemical disorders, leads to serious skin problems.