The Philips BlueControl7 blue LED light is UV-free and induces natural relief processes in your skin. It helps to control rapid cell proliferation2 and inflammation3 associated with plaque psoriasis. Light is generally understood as referring to the visible range of the electromagnetic spectrum. For humans, this visible range comprises wavelengths from around 400–780 nanometres (nm). The blue LED light spectrum is in the range of 400–490 nm and has special effects on the human body. The blue LED light used in Philips BlueControl has a wavelength of 453 nm, which is absolutely UV-free. Ultraviolet rays in contrast belong to the invisible light spectrum. UV light has a shorter wavelength and higher energy than visible light. The higher energy of UV light can be harmful to skin depending on the dose.