I dropped my iPhone and something weird appeared on it. It's very small and less than a centimetre. I thought it was a crack but if I run my finger over it, there's no crack. It's only visible in daylight and there's no effect on what's on the screen so is it glue leaking or something? It looks like tiny dots close up, inside the screen. It didn't come out clearly in the picture but I've attached it anyway.