My Black Eye

I have no idea why or how but for the last few days I have had a black eye. It came up last week and got worse over the weekend. I don't know why. No one punched me so I must have gotten something in it at work or something? I woke up Tuesday and could barely see because it was that puffy and swollen. How odd. Today it was ok but it still feels like a black eye when I blink. I really have no idea how it happened.