The invention relates to a device for cosmetic treatment by light comprising:&mdashat least one light emission source (10)&mdasha reference surface (5) fixed with respect to said light emission source,&mdashat least one distance sensor (20) for measuring a distance between the reference surface (5) and a cosmetic treatment area (30) of the skin,&mdasha microcontroller (3) suitable for controlling the emission power of each light source (10), in which the emission power of each light source is slaved to the distance measured by the sensor.
