In light of the topic of weather, Tolkien seems to use light literally as well as figuratively (no pun intended).
For instance, let us take Eowyn in the House of Healing. For the longest time Faramir was showing Eowyn his love for her, but she was still in her "winter", because she has not yet let go of her love for Aragorn. But after the downfall of Sauron, Eowyn finally "understood", as the book said. Now, does not the word "enlightened" have a more or less similar meaning? Then we see that as Faramir and Eowyn walk together after this, a
light was about them.
I also noticed in the Battle of the Pelennor Fields that after Eomer found out that it was Aragorn and the Grey Company who were in the ships after all, it was mentioned that he threw his sword, which caught light. Or something like that.
It's really hard to explain things without the books in hand. Would anyone please help me by verifying these from the books? Any help would be deeply appreciated.