How some watches needle emit green light when it in dark area?

Luminous paint is used on the hands which glows in the dark. It is a water-based acrylic varnish containing the luminous material.

Where that paint get energy to glow?

Hi Kesavan, I gave a pretty in depth answer to your question the last time you asked it. It can be found here:

https://www.askmehelpdesk.com/physics/emiting-light-240750.html

There is no need to post a new topic!

Amricca, as my answer in the above link says, the material is phosphorescent, not luminescent.

Hey thanks, I learned something. I looked it up on line to answer his question, guess the sites I looked at had it wrong.