This gives the ability of watches to become readable in dim light, and even underwater. This is achieved by applying luminescent material, such as Super-LumiNova, to the hands, hour markers, or numerals. In daylight it absorbs light, which it then progressively emits at night.
This feature is crucially important in diving and military watches, which should be dependable in terms of visibility. This practical feature marries function with aesthetic appeal, often striking the visual presence on the watch face.
