Luminous Clocks

Do Luminous clocks glow in the dark?     

Answer: Only for a very short period of time time.

Luminous clock hands have been used for over a century, and radium was initially used to paint the hands. However, radium is a highly radioactive substance that posed a significant health risk and deaths to the workers who applied it. In the 1960s, the use of radium in clock dials was banned due to its health hazards. 

After radium, Tritium came into the picture, which was less radioactive than radium and was a safer alternative to Radium; however, it was expensive and not an affordable option for home use.

In the early 1990s, a new alternative, strontium aluminate, replaced other materials as the customary material for luminous clock dials. It is a non-radioactive material that absorbs light and slightly reemits it temporarily, making it glow in the dark for several minutes. However, it is essential to note that any glow from luminous clock dials does not last long, and after a few minutes, it completely disappears. 

While some manufacturers claim that their luminous clocks glow all night, this is not the case, and most pictures of luminous clock dials online that appear bright have been photoshopped to make them appear brighter than they actually are. 

Today, the only way to have a clock that is readable all night is to have one with LED(s) to illuminate the clock dial.