Understanding Rolex Lume: Why Your Watch May Not Glow

A commenter recently asked a great question on the Everest Journal:

“Why can’t Rolex manage to have hands/dials that can be seen in the dark? I’ve had my GMT-Master since 1985 (purchased new); I’ve replaced the face (all done by certified Rolex repairmen) and in both cases, the new and the replacement face and hands, the ability to see anything in a dark environment is nonexistent.”

It’s a fair question—and one that reveals a lot about Rolex lume, how it’s changed over the decades, and why some Rolexes just stop glowing.

Let’s break it down.

Radium, Tritium, and When It All Changed

Rolex Submariner 'King Sub' ref. 6200 with Radium Lume. Image Source: RedBar Blog

Rolex first used radium as its luminescent material from the 1910s through the mid-1960s. It glowed brightly and continuously—but it was also radioactive enough to damage dials over time and pose health risks to the workers who applied it. By the early 1960s, Rolex began transitioning to tritium, which is much less radioactive and safer to handle. By 1963, the switch was essentially complete.

Rolex Explorer II ref. 16570 with tritium lume. Image Source: Ticking Way

From the mid-1960s to the late 1990s, nearly every Rolex used tritium for dial and hand lume. You can spot a tritium dial by checking the bottom of the dial, near 6 o’clock. If it says “T SWISS T” or “SWISS – T < 25,” you’re looking at tritium.

The thing is, tritium doesn’t glow forever. Its half-life is about 12.3 years, meaning the brightness slowly fades over time—and after 20–30 years, it’s often barely visible, if at all. So if you own a Rolex from that era and your lume doesn’t work in the dark anymore, it’s not broken. It’s just tritium, doing what tritium does.

But What If My Lume Was Replaced?

Image Source: Tropical Watch

Even if your dial or hands were replaced during a service, it’s entirely possible they were replaced with more tritium parts. Rolex continued installing tritium service dials until the late 1990s, when they fully transitioned to a non-radioactive, photoluminescent material called Luminova—developed by Nemoto & Co. in Japan and later licensed for use in Switzerland. By 2000, Rolex was using Super-LumiNova, a slightly refined version of the same material.

Rolex Chromalight glowing. Image Source: Bob's Watches

Then, in 2008, Rolex introduced Chromalight, their own proprietary compound. It glows blue instead of green and is standard on most models today. All three of these modern compounds (Luminova, Super-LumiNova, and Chromalight) need to be “charged” by light exposure, but they don’t decay over time the way tritium does.

So unless you’ve had your watch serviced post-2000 and were given a modern dial or handset, there’s a good chance your replacement parts—like your originals—were still tritium. Which brings us back to the 1985 GMT-Master: if that watch still doesn’t glow after having its face and hands replaced, that replacement likely happened before Luminova became the new standard, or the service parts themselves were already aging.

What About Modern Rolexes?

Image Source: Millenary Watches

If your Rolex was made in the past 20 years and the lume isn’t glowing, it’s probably not a materials issue—it’s a charging issue. Modern lume needs UV light to glow in the dark. Try putting the dial in direct sunlight or under a UV lamp for a few minutes, then bring it into a dark room. If nothing happens, you may have a dial or hands that were damaged during service, or parts that have been swapped and mismatched. That’s rare, but worth checking with a watchmaker if you're unsure.

Otherwise, if your Rolex lume was made after 2000, it should still glow—just not all day long. That's by design.

Why It Matters

Understanding the lume on your Rolex is more than just a late-night legibility thing—it’s one of the clearest indicators of when a watch was made, what parts have been changed, and how original it really is.

Tritium dials from the '60s to '90s will fade and change color over time, developing patina that many collectors love. Modern Rolex lume will stay bright and white for decades, glowing on demand when properly charged. One is not necessarily better than the other—they just tell different stories.

Header Image Source: Atelier De Griff