Abstract: An illuminator adapted to be illuminated by a fluorescent lamp mounted in a light fixture when the fluorescent lamp is emitting light to indicate that the fluorescent light is turned on. The light fixture is of the type having a fixture casing for holding the fluorescent lamp and including a specular reflector for reflecting the light emitted from the lamp generally downwardly toward an area to be illuminated without the light passing through a light diffuser. The illuminator comprises a generally transparent or translucent illuminator body, and illuminator-mounting flanges adapted for mounting the illuminator body on the fixture casing or reflector without the body interferring with or intersecting light transmitted generally directly downwardly toward the area to be illuminated. The body includes material having such an index of refraction and surfaces so contoured that a portion of the light originating from the fluorescent lamp is refracted at a sharp angle (e.g.