Initially developed for **military convenience**, luminous watches allowed soldiers to tell time in the dark or dimly lit

Initially developed for **military convenience**, luminous watches allowed soldiers to tell time in the dark or dimly lit environments without risking exposure by using an external light source. The first luminous watches, around 1910, utilized radium-based luminous paint.

It’s well-known that **Marie Curie** discovered radium, earning a Nobel Prize. However, less known is that Pierre Curie showed symptoms of radiation overexposure before his accident, and Marie Curie eventually died from radiation exposure. Radium is radioactive and toxic, and even in small quantities with the protection of the watch glass, it could still pose a risk to human health.

By the **1950s**, the use of radium in consumer products was gradually restricted. Tritium, another radioactive material, became the alternative for watch luminosity. Tritium is safer than radium, emitting only β particles with a very short range of 0.4 cm and weak penetration power, unable to pass through the watch glass. Given its minimal use, it does not harm the wearer.

In the **mid-1990s**, a new type of luminous material emerged: **Luminova**, a non-radioactive, eco-friendly substance. Its main component is an inorganic aluminate, stable and resistant to discoloration even after prolonged use.

Today’s luminous watches, utilizing advanced, safer technologies like Luminova, pose no harm to humans, allowing everyone to safely enjoy their glow.