Discover the History Behind the Three Types of Glow-in-the-Dark Materials Used in Wristwatches

Have you ever wanted to know how to make your watch shine in the dark? Well, you're in luck! Luminous watches have been invented, allowing individuals to wear a stylish watch even when the lights are out. In this article, we'll take a look at the evolution of luminous watches, examining five distinct types and their unique characteristics. Get the inside scoop on how these watches have developed over time and what they can do for you now.


Doctor Identifies Symptoms Connected to Radium-Infused Watch Poisoning

Radium, a luminous substance that had been discovered by the illustrious physicist Marie Curie in 1898, was one of the first materials ever used for watch dials.

The radium material used in this product is a blend of radium and zinc sulfide. It is skillfully applied onto the hands and numbers of the watch, resulting in the emission of mesmerizing, albeit unstable, light. It is worth noting, though, that only a select few Radium watches possess the remarkable ability to emit a vibrant and consistent glow for an impressive period of 50 years before eventually fading away.


According to scientific studies, the Radium watches that were manufactured prior to the 1960s no longer exhibit luminescence as the zinc sulfide element has undergone complete ionization.

The use of Radium material in watches has been phased out due to its toxic nature, which posed risks to both users and workers involved in its production.

GMT Master 6542 of Rolex used Radium material

According to scientific research, exposure to Radium’s gamma rays and radon gas can lead to the development of cancer in humans. Furthermore, studies have indicated that the watch dial during that era could potentially induce illness or even result in radiation poisoning, leading to fatality.

Historically, the detrimental effects of Radium were widely acknowledged and eventually led to its permanent prohibition on the use of watches, beginning in the 1950s.

Two New Tritium Watches Unveiled

During the period from 1968 to 1978, Tritium was discovered and subsequently established as a safer alternative to Radium for military applications.

Tritium is a radioactive compound of hydrogen atoms that emits low-energy beta particles. It has a relatively long half-life of 12.32 years, although some watches are designed to extend its lifespan up to 25 years. Tritium is typically sealed in glass tubes to provide luminescence.

Tritium lights up in the glass

This material exhibits continuous luminescence and does not require charging. It can be produced in a variety of colors.

Tritium serves as a gas enclosed within the tube-shaped hands of watches, which are also filled with phosphor powder. When electrons from the tritium gas interact with the phosphor powder, it results in the emission of light.

Tritium watch

This material is not only utilized in the production of watches, but it is also employed to craft luminescent details on aircraft or weapon scopes.

The luminescence ability of Tritium, due to its half-life, gradually diminishes over time. After a span of more than ten years, it eventually ceases to function. Consequently, Tritium is not regarded as the most suitable material for long-lasting watches.

Add a Touch of Glow: 3 Phosphorescent Watchfaces for Your Smartwatch

In 1669, German alchemist Hennig Brand made a groundbreaking discovery by finding phosphorus, a luminous substance that emits light in the absence of burning.

Phosphorescent has a rich history of use in East Asian countries like Japan and China, where it has been employed for centuries in renowned artwork and traditional adornments.

Phosphorescent phenomenon in nature

During this period, Europeans embarked on a journey of discovery and experimentation with this radiant substance. Over time, it found its way into the hands of watchmakers who skillfully applied it to hour markers and watch hands, enabling users to easily read the time even in low lighting conditions.

The two most commonly used compounds for phosphorescent materials in watches are Strontium Aluminate (SrAl2O4) and zinc sulfide (ZnS). These compounds, known for their ability to enhance brightness and longevity, are often preferred in high-end functional watches.

Phosphorescent is commonly utilized in watches designed for outdoor use, showcasing excellent performance in both illuminated and dark settings. These watches are particularly favored for diving and sporting activities.

The most popular types of phosphorescent watches currently in use include SuperLumiNova, LumiBrite, Nautilite, and NoctiLumina. These watches are made using the same formula as Strontium Aluminate and are composed of a combination of metal compounds with a sulfide base.

Phosphorescent watch

SuperLuminova, developed by Nemoto in 1993, is a luminescent material commonly used in both Japanese and Swiss watches.

This material is designed to effectively absorb both natural and artificial light in order to recharge and emit light. By harnessing this innovative technology, it is able to conserve energy and promote environmental sustainability. Additionally, it prioritizes human health and is free from any harmful effects.

SuperLuminova watch

SuperLuminova’s luminescence has a shorter duration compared to Tritium, lasting only 2 to 10 hours, which requires periodic recharging.

The following is an article that introduces three types of luminous materials commonly used on wristwatches and discusses their origins. By providing this information, our intention is to enhance your understanding of this particular type of timepiece.