Holding a luminous watch

What Is A Luminous Watch? Everything You Need To Know

Ever since the invention of luminous watch dials, we have been telling the time in the dark. Before their invention, telling the time when the sun went down wasn’t so easy. You had to rely on lights from elsewhere to help you tell the time at night.

Fortunately, luminous watch dials have been around for over 100 years and we have been keeping on top of the time in the decades that followed. But do we know how luminous watches work or even what they truly are?

Wonder no longer! We are going to take a deep dive into everything you need to know about luminous watches.

What Is A Luminous Watch?

Luminescent dial watch

In short, a luminous watch is one that glows in the dark. It makes telling the time super easy, even when there is no light around. Considering that many watch owners choose to stay away from digital timepieces, being able to tell the time in the dark is a necessity.

Thankfully, glow-in-the-dark watch hands make telling the time at night painless. Our watches don’t mysteriously stop working just because there isn’t any light. With luminous hands, we can see exactly where they are pointing.

Some watchmakers will also ensure the hour markers are luminous to remove all doubt about telling the time at night. There is even the possibility of choosing a full luminous dial watch, that gives the wearer even better vision in the dark.

How Does A Luminous Dial Watch Work?

Glow-in-the-dark watch

It’s all well and good knowing what a luminous watch is but not many of us understand how they work. How luminous watches work comes down to a little bit of chemistry.

Objects that glow in the dark do so thanks to a property known as phosphorescence. Phosphorescence is derived from photoluminescence. Photoluminescence allows materials to glow in the dark after exposure to light.

Photons in light sources are stored by the photoluminescent materials and emit it when it is dark. This is how watches that glow in the dark get their shine.

Materials on watch hands, or sometimes entire faces, are given a photoluminescent coating. These materials shine at the right time. Photons are absorbed from a light source by photoluminescence material. In watches this material is phosphorescent.

After absorbing the photons from the light source, watch hands coated in phosphorescent material will slowly release the light back out. This is typically over a period of many hours, and can often last all night.

Essentially, luminous watches trap light thanks to their phosphorescent coating and gradually leak it back out throughout the night.

The Downside Of Luminescent Dial Watches

Radioactive sign

Unfortunately, there are a few drawbacks to owning a luminescent watch. For starters, glow-in-the-dark material doesn’t last forever, so at some point watch hands will need to be replaced.

Watches coated in phosphorescent many years ago may only shine for a little while or potentially not at all. That brings about a dilemma for many vintage watch owners and collectors.

If you wish to continue to tell the time in the dark once the luminescence wears out you have to replace the original parts of the watch. That means choosing between telling the time in the dark or keeping your watch as original as possible. Opting for the former could mean seriously dropping the value when the time comes to selling your watch.

Today owning a luminous watch is safe. When they were first introduced at the beginning of the 20th century, however, that wasn’t the case. Many years ago, luminous watches were coated in radium to give them their glow. Radium is radioactive and can cause harm to anyone coming into contact with it.

The hands of watches were coated in radium which would then glow immediately because it works differently from modern watches. Radium doesn’t require a light source to help it glow, it can do that all by itself.

Unlike phosphorescent-coated watches, radium-laced watches would only glow for a couple of years before needing a fresh coat of paint. Despite the fact radium dials don’t glow in the dark after a couple of years, they retain their radioactivity for up to several decades.

Developing Luminous Watches Safely

Caution warning

It was clear to many watchmakers that radium-coated watch dials were not sustainable. They began searching for alternative ways to allow people to tell the time in the dark.

Tritium was an acceptable alternative to radium thanks to its lower level of radiation and longer half-life. Likewise, promethium emits low-level radiation but it doesn’t have much of a glow.

Over time, tritium paint for watch hands also loses its photoluminescence but at a much slower rate than radium which makes it the better choice. Although these solutions were good, the search for something continued.

That is where Luminova and Super-Luminova enter the luminous watch scene.

Modern Luminous Watches

Glow in the dark

The watch industry continued to research photoluminescent materials to use on dials to make them glow. The desire to move away from radioactive materials altogether was strong. A phosphor that glows for hours after being exposed to light was required.

In 1993 a solution presented itself. Luminova was invented in Japan in the ’90s and changed the watch industry. Later, this developed into Super-Luminova which is charged by light and glows for hours without any radioactivity.

While luminosity diminishes eventually, Super-Luminova is the answer the watch industry was searching for. In general, it seems like a long-lasting material and one that has largely become the industry standard thanks to its safety.

Now, if you’re looking for men’s luminous watches you no longer have to get your Geiger counter out to check for radiation.

Interested In A New Watch?

Here at Uniform Wares, we offer beautifully designed British watches crafted by Swiss engineers. You can design your watch to suit your taste thanks to our deconstructed method of investing in a watch.

You can choose watches by the face first before adding whichever strap you prefer. Our straps come in a variety of colours and materials, like gold or silver, so you can always find the perfect watch for you.

We only use high-quality materials for our Swiss-made timepieces. Check out our elegant options to find your next luxury watch.

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