Optical Brighteners
EIELSON AIR FORCE BASE, Alaska--Pictured, the Army Combat Uniform, with material identical to the Airman Battle Uniform, shows the difference optical brighteners make under ultra-violet lighting. Laundry detergents with additives known as "optical brighteners" make the material of the ABUs more detectable by night vision equipment and make the ABU more visible in a low-light environment of any kind. Optical brighteners are chemicals that absorb the ultraviolet and violet region of colors in a fabric. They trick the eye into seeing a brighter shade and reflect more light. (file photo)