The quest for the perfect luminous timepiece has been long and sometimes tragic, but today modern technology allows watch brands to safely generate that captivating glow.
FROM TOP: This Breitling Cockpit B50 watch ($7,200) features a titanium case with a black dial and LCD (liquid crystal display) backlighting. An analog/ digital timepiece, it offers a chronograph (measuring to 1/100th of a second), a tachometer, an alarm, a calendar, and more. Horologio, The Grand Canal Shoppes at Venetian and Palazzo, 702-733-0016
From Omega, this Speedmaster Skywalker X-33 Solar Impulse Limited Edition watch ($5,900) features a blue and green dial with white transferred indexes and hour markers coated with white Super-LumiNova. It is powered by a multifunctional quartz chronograph movement. Horologio, The Grand Canal Shoppes at Venetian and Palazzo, 702-733-0016
This Tudor Pelagos watch ($4,125) has a selfwinding movement inside a 42mm titanium case as well as a unidirectional rotating bezel with a black ceramic disk. Water resistant to 500 meters, it features Super-LumiNova hands and markers. Wynn & Company Watches, 702-770-3520
From IWC Schaffhausen, this Aquatimer Automatic 2000 watch ($10,100) houses a mechanical self-winding movement made in-house. Water resistant to 2,000 meters, it is crafted in titanium and has a rubber strap featuring the SafeDive system on the buckle for security. IWC, Encore Las Vegas, 702-770-5471
A luminous watch is designed to make nighttime or underwater reading easier, but perfecting the technology behind that magical glow has taken more than a century, with tragic results along the way.
In the late 18th and early 19th centuries, watchmakers attempted to add luminescence to timepieces by crushing iridescent shells and volcanic stones, then painting the resulting material onto the dial. But true luminescence wasn’t possible until 1898, when Marie and Pierre Curie discovered the radioactive element radium.
In 1914, a company called the Radium Luminous Material Corporation (later the United States Radium Corporation) began using radium to produce a luminescent paint it dubbed Undark. U.S. Radium and similar companies hired thousands of workers (mainly women) to paint watch dials with the substance. They were instructed to lick the tips of their fine brushes to keep them pointed and create sharp, legible numerals. Unfortunately, what the workers didn’t know is that the alpha and gamma radiation emitted by radium is deadly when ingested, and many of them became ill and died.
Thanks to the efforts of a group of workers known as the Radium Girls, manufacturers that employed the material were forced to address the dangers of working with it, leading to an eventual ban on the practice. This spurred the development of new, photoluminescent paints, which absorb photons from external light sources and emit them over time, producing a safe glow.
From Ball Watch USA, this Engineer II Marvelight ($1,899) contains 14 tritium gas tubes below the crystal, resulting in hour, minute, and second hands that are luminous for night reading. Housing an automatic movement, the watch is antimagnetic, shock resistant to 5,000 Gs, and water resistant to 100 meters. Tourneau Time Dome, The Forum Shops at Caesars, 702-732-8463
In the 1990s, a new, nonradioactive photoluminescent substance was unveiled under the brand name Super-LumiNova. A strontium aluminate– based material, it is produced in a host of colors, allowing watch numerals, markers, hands, and other dial accents to glow blue, green, or even reddish orange, depending on the mix used. Over the next two decades, research and development steadily improved the product, which is now up to 10 times brighter than the zinc sulfide–based photoluminescent materials used 20 years ago, making Super-LumiNova the current market leader for creating luminous watch dials.
But it’s not the only source of timepiece luminescence. For their dive and pilot watches, a handful of brands prefer a device known as a gaseous tritium light source: a tiny glass tube encapsulating a radioactive material (MB-Microtec is a major developer and supplier of them). Together, a group of tubes can be as much as 10 times brighter than applied Super-LumiNova.
They also last longer. While Super-LumiNova can begin to dim after a few years, tritium capsules stay bright for 15 to 20 years. And their luminescence is constant during that time, unlike Super-LumiNova, which must be exposed to light to regenerate its glow. Of course, the search for new, more powerful ways to give watches that ultrachic glow continues, but for now, these methods shine brightest.