When I got my contacts (about a year ago) my eye doctor told me not to sleep with them in, and if I did fall asleep to take them out as soon as I woke up/realized that I still had them in. However, sometimes I'm too lazy to take them out and I sleep with them in anyway. It makes my eyes slightly dry sometimes, but is that the only reason I'm not supposed to sleep with them in? Or is there some other reason that I should be aware of? Could I be harming my eyes?