This question I understand! when I was on oral abx last year I finally realized that everytime I was in walmart I got sooooooo sick. I soon made the connection that it was the fluorescent lights that made me so sick. I would sweat, get nauseau, and would literally have to sit down. I began wearing sunglasses when in situations like that. I was taking doxycycline and flagyl. I believe it was the doxy due to the light sensitivity when taking it.