I've always had this niggling problem of my specs not sitting correctly on my bridge. Well. I've finally realized the reason - my eyes aren't on the same level; my right eye drifts upwards ever so slightly. It's not really noticeable if I'm not wearing specs.. but since I do wear them most of the time, it becomes obvious (well, in my opinion anyway) when the top of my right eye peeks over the rim. Woe is me... I don't have a symmetrical face and will never ever be considered among the 'beautiful' people in life...