Solar radiation is electromagnetic radiation emitted by the sun. At the earth's surface it consists mainly of visible light and infrared radiation. Light energy is emitted as waves - the shorter distance between the waves the higher the energy. Light is part of the electromagnetic spectrum that is visible to our eyes. The electromagnetic spectrum stretches from long, very low-energy waves to short, ultra-high energy waves. Radio waves are very long, and visible light is medium length, whereas gamma rays and x-rays are short. The shorter the wave is, the higher the energy and the more damage that can be done to our bodies. Between visible light (400-800 nm) and very high energy x-rays, there is high-energy ultraviolet light/radiation (UVR). UVR is invisible, high-energy radiation, that is capable of causing damage to living organisms.