Black Lights (1960s)
In the late 1960s, black light fluorescent bulbs made everything white glow a little bit brighter. Black lights were also used to communicate in secret; black light is able to reveal secret symbols written on paper. In nightclubs, when black light was coupled with strobe lighting, an eerie purple haze was created.
Black light is also known as UVA light or just ultraviolet light. The light emits long wave ultraviolet light and not much visible light. Lamps contain violet filler material that blocks visible light and allows the ultraviolet light through, giving the lamp a violet or blue glow when in operation.
Bug zappers use black lights. Black lights are used in medicine, science and in forensics. These black lights are called Wood’s Lamps. You can use black light to detect counterfeit money. Tanning beds use strong UVA sources. Low level UVA emissions are not harmful to the skin or eyes, but the strong sources (like in tanning beds) are harmful and require protection.