Klieg Light
A klieg light is an intense carbon arc lamp, invented by brothers Anton and Johann Kliegl in the early 1900s and widely used in early Hollywood filmmaking. The light is produced by two carbon rods heated until they form a glowing arc between them — bright enough to shoot daytime scenes at night, and visible from miles away on a clear night.
The name became so synonymous with powerful studio lighting that "klieg light" turned into a generic term for any bright spotlight, regardless of the actual technology. Today, the term is mostly figurative — used to describe intense public scrutiny or the spotlight of attention.
One notorious side effect: prolonged exposure caused actors to develop "klieg eye", an inflammation and dryness of the eyes from the harsh UV radiation. The lights also ran extremely hot, requiring operators to wear protective gloves and replace the carbon rods every two hours.
After the film industry converted to sound in 1927, the sputtering noise of carbon arcs made them incompatible with audio recording, and they were gradually replaced by quieter incandescent fixtures.
In the book, a Klieg light is used for the patient in the operating room.