Every once and a while I read about a character's eyes being bright or dark but I don't actually know what this means. I interpret dark eyes to mean that they are a dark brown, almost black color. Does bright then mean that they are blue or green or that they stand out or that the character is excited? Then there are descriptions about how someone's dark eyes flash in the moonlight / torchlight / lantern light. I assume this means that their eyes reflected the light for a second or that those observing see that the character is suddenly angry. It's strange, I've always assumed I knew what these phrases meant but I've never actually asked a writer how what they take the phrases to mean or how they should be used properly. Thoughts?