The U.S. Navy SEALs began using it in the 1990s to help heal wounds quickly and to help regenerate damaged muscle tissues. LED Light Therapy uses colour wavelengths of visible light which have specific skin benefits. Red light therapy (RLT) is a treatment that may help skin, muscle tissue, and other parts of your body heal. LED (light-emitting diode) is a "lower energy form," in which the light is absorbed by the molecules in the skin, which in turn "alters the biologic activity or the activity of nearby cells." It exposes you to low levels of red or near-infrared light. LED light therapy has an established history of skin uses.