Can I rub my eyes or remove eye mucus/crumbs/”sleepies” on Shabbos? What if in the process I will be removing black eye makeup that got stuck to the mucus and is now unwanted because its off my eye?
You may rub your eyes and remove any dried mucus. Additionally you may also remove dried makeup with you fingers or water, but not with a wet cloth or tissue because that would be sechita.
It is not an issue of tzovaya, because there is no issue of removing color that has no meaning, only when it is a picture of something or a letter. It is not an issue or borer because it is on the body, and because it is something that it is the normal cleaning of the body. See Orchos Shabbos 15-59, ftnt. 85, Shmiras Shabbos Khilchoso 3 ftnt. 7.