Allegedly, it's LED now: 'The small light bulb was replaced by a LED diode, but the intensity of the tired firefly remained' https://www.hodinky-365.com/blog/

Allegedly, it's LED now: 'The small light bulb was replaced by a LED diode, but the intensity of the tired firefly remained' https://www.hodinky-365.com/blog/casio-f-91w-review https://www.hodinky-365.com/blog/casio-f-91w-review I wear F-91W every day and FWIW, the light is adequate to see time at night.