Lume
Lume is the glowing material on the hands and markers that charges in light and glows in the dark, so you can read the watch at night. The most common types are Super-LumiNova and Seiko's LumiBrite.
Readability in the dark comes down to how efficiently the luminous material stores daylight or artificial light, and how long it gives that charge back. It is not radioactive: it absorbs light, then releases it slowly.
What separates good lume from weak lume
Two qualities matter, and they are judged together:
- Brightness: the intensity right after you leave the light
- Duration: strong lume stays legible hours later, not minutes
Budget watches often have weaker or uneven lume, where some markers fade well before others on the same dial.
The common types
The two materials you will see most are Super-LumiNova and Seiko's LumiBrite application. LumiBrite glows strongly and gives a diver a clear advantage in dark water, which is why luminous hands and markers are a priority on any dive watch, right alongside a legible bezel.
To see how lume performs in practice, read our guide to the best dive watches under $500.
Related terms
Watches that show this
Frequently asked questions
Is watch lume radioactive
No, modern lume is not radioactive. It absorbs daylight or artificial light and releases it for a while in the dark, then recharges the next time it is exposed to light.
What makes lume good
Good lume is both bright and long-lasting: it stays legible hours after you leave the light, not just minutes. Budget watches often have weaker or uneven lume where some markers fade before others.
What is the difference between LumiBrite and Super-LumiNova
Both are the common lume materials used today. LumiBrite is Seiko's application, glows strongly, and gives a diver a clear advantage in dark water, while Super-LumiNova is the other widely used type across the industry.