What Causes Pupils To Keep Rolling Up?

My pupil keeps rolling up so It seems like I m looking up but the thing is I don t even notice I m doing it and I cant stop it from rolling up but even more strange when my pupil is looking up I can still see right in front of me not up I only know this happens because family and friends have pointed it out and I can see it in the mirror. Age:14 Name:Lucy. It has been doing this for years now. I am not Lucy but I told her since ive knowning her since nursery I would help her look into it any help for her would be appreciated thanks.