I'm deciding that Dwarves' eyes reflect in the dark based off of that one line in The Hobbit and also a couple bits of Unfinished Tales where it describes Mîm's eyes as having a sort of red glint to them.
I can't find anything that canonically states that Dwarves have better night vision, but it's a common enough fanon thing that I'm just going to accept it as canon, and therefore why their eyes glow.












