Optical Whitening agents are the chemicals, which are added to silk blouses, linen slacks, underwear etc. These make use of the process of fluorescence and make the clothes whiter and brighter than they are. They are functional as the fluorescent brightening compounds, the chemical compounds which provide a whitening effect to several fabrics. Optical Whitening agents can absorb the light in the ultraviolet or blue region. They are also added to detergents for giving them the whitening quality.