[flu̇′res·əns ′dij·əd·əl ¦im·ij·iŋ ′mī·krə‚skōp] (optics) An instrument for observing images formed by emitted fluorescent light; consists of an electronic camera or a laser-photomultiplier scanning system, an analog-to-digital converter, and a computer that manipulates the digitized signal and converts it back to analog form for display.