Question: Since lightsabers give off a visible glow, I could see a Jedi or a Sith using their lightsaber as a lighting source. They were already used as tools (at least in Episode I) so there are some non-violent uses to a lightsaber. Has any Jedi or Sith used their lightsaber in this manner in canon works?

Answer: 
In *The Clone Wars: [Weapons Factory](http://starwars.wikia.com/wiki/Weapons_Factory)* (S02E06), Barriss Offee and Ashoka Tano use their sabers to provide light when they are trapped beneath some rubble.

![Barriss & Ashoka](https://i.stack.imgur.com/XYTq8.jpg)

In the following episode, *[Legacy of Terror](http://starwars.wikia.com/wiki/Legacy_of_Terror)* (S02E07), Obi-Wan and Anakin use theirs to provide light as they descend into a temple. 

![Obi-Wan & Anakin](https://i.stack.imgur.com/cffqH.jpg)

![Obi-Wan & Anakin](https://i.stack.imgur.com/8u7Tc.jpg)
When Luke is being tested by Yoda at the tree of the Dark Side, he lights his saber as he enters the tunnel. I always assumed it was in order to see by its light.

This is supported by the official novelization as mentioned by [Valorum](https://scifi.stackexchange.com/users/20774/valorum).

> 
> He held his glowing sword in front of him and noticed an object on the cave floor. Pointing his lightsaber downward, Luke illuminated a black, shiny beetle the size of his hand. In an instant, the thing scurried up the slimy wall to join a cluster of its mates.
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