A physical process of converting high-frequency radiation (most commonly ultraviolet light) into visible light. Fluorescent materials—such as fluorescent pigment colors—absorb ultraviolet light and discharge it as bright visible light. A common example of other fluorescent materials are the phosphors which coat the inside of a cathode-ray tube, which fluoresce to produce the components of a computer or television display. Ultraviolet light is used to detect certain naturally fluorescent materials—for example, fungi and other organisms responsible for food spoilage will fluoresce, and ultraviolet light can be used to detect them. Fluorescent dyes are also used in medicine, where they can be used to identify tumors and other medical problems. Fluorescent materials are also used in laundry detergents, and it is the fluorescence of these materials which produces the brightening effect of whites and colors.