The answer is visible light. Most of the solar radiation that reaches the Earth is made up of visible and infrared light. Only a small amount of ultraviolet radiation reaches the surface of the earth. Ordinary sunlight or solar radiation is broken into visible light (0.4 nm - 0.8 nm), ultraviolet light ( 0.4 nm) and the infrared radiation (0.8 nm). The visible light makes up almost half of the total radiation reaching the surface of the Earth.