Lume
Lume is the glowing material applied to the hands and markers; it charges in light and glows in the dark, letting you 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 releases that charge afterwards. It is not radioactive: it absorbs light, then gives it back slowly.
What separates good lume from weak lume
Two qualities matter, and they are judged together:
- Brightness: the intensity in the moments after you leave the light
- Duration: good 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 encounter 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 sit near the top of the list for any dive watch, alongside a legible bezel.
To see how lume holds up in real snorkelling and diving, 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 on the same dial.
What is the difference between LumiBrite and Super-LumiNova
Both are the common lume materials in use today. LumiBrite is Seiko's application, glows strongly, and gives a diver a clear advantage in dark water, whereas Super-LumiNova is the other widely used type across the industry.