Fluorescent lamps
Emit ultraviolet
light

Ultraviolet radiation is present in sunlight. When sunlight hits your body, the ultraviolet radiation enables your skin cells to produce vitamin D.  The radiation can also kill germs. It is invisible and its wavelength is shorter than visible light. In the electromagnetic spectrum, it is next to violet light at one end of the visible light band. Radiation can be detected with a fluorescent material. When struck in a dark room, the fluorescent material glows and gives off light.