To cleanse the palate.
Dear Prudence,
I told my husband that it is unnerving for me to have conversations with people if they are wearing sunglasses and I am not. It bothers me that I can't see their eyes but they can see mine. Their failure to remove their sunglasses so we can make eye contact strikes me as rude. My husband thinks it is my problem. I think etiquette dictates that they remove their sunglasses, provided they don't have a real medical reason for wearing them. Who's right?