Infrared optics also referred to as IR optics, are heat absorbing filters. Infrared optics are designed to reflect or block mid-infrared wavelengths but allow visible light to pass. Infrared optics are very often used in devices that have bright incandescent light bulbs, overhead projectors, for example, and are used to prevent unwanted heating. Infrared optics filters are also used in solid state video cameras, and this is to block Infrared due to the high intensity of many camera sensors, to near infrared light. Infrared IR radiation is electromagnetic radiation whose wavelength is longer than that of visible light. Infrared optics are implemented in many industries, fabrication/welding and electronics being just two examples.