Patent ID: 8226634

Claim:
A method for protecting in vivo human skin against photodamage caused by an exposure to a damaging radiation including ultraviolet radiation, said method comprising: irradiating the human skin before the exposure to the damaging radiation with a protective radiation, the protective radiation including radiation having a wavelength larger than the wavelength of the damaging radiation, the protective radiation including non-coherent light having a bandwidth of from about 10 nm to about 50 nm, the protective radiation being irradiated onto the human skin under conditions suitable for reducing photodamage to the human skin caused by the damaging radiation; said irradiation of the human skin before the exposure to the damaging radiation with a protective radiation including irradiating the human skin with a first pulse having a power density between 20 and 100 mW/cm 2 ; irradiating the human skin with a second pulse; emitting the first pulse for a duration of about 100 microseconds to about 5 milliseconds; and separating the first pulse from the second pulse by an inter-pulse interval of about 1 microsecond to about 1 millisecond; the protective radiation including at least two pulse trains, each pulse train including the first pulse and the second pulse, the irradiation of the human skin before the exposure to the damaging radiation with a protective radiation further including emitting a first pulse train; and separating the first pulse train from a second pulse train by an inter-pulse train interval of about 500 microseconds to about 2.25 millisecond; wherein the inter-pulse train interval is greater than the inter-pulse interval; and wherein said irradiation of the human skin is performed under non-thermal and non-ablative conditions in which temperature of said human skin remains below a predetermined overheating temperature, said predetermined overeating temperature being about 5° C. above a maximal non-pathological in-vivo human skin temperature; said method further comprising exposing the human skin to the damaging radiation after irradiating the human skin with the protective radiation; whereby irradiation of the human skin before the exposure to the damaging radiation with the protective radiation reduces damages to the human skin caused by the damaging radiation as compared to human skin that was not subject to irradiation with the protective radiation.