The layer you are referring to inside the eye that covers the white area or sclera is called the conjunctiva.However delicate these layers may seem they do not disengage by forceful eye rubbing in most instances. What you may be observing is a mild conjunctival oedema. This is sudden and startling in certain instances where the patient inadvertantly has some remnant of an irritaing substance on his hands during rubbing like perfume, lotion, talc, chilli powder household sprays or pesticides being used at the time. The oedema subsides as rapidly as it starts. An oral dose of antihistaminic such as Cetrizine or Levocetrizine tablets work well along with an antiinflammatory eye drop preparation like ketorolac used 3 times for a couple of days works fast and well. There is no visual damage or lasting effects of a single episode of conjunctival oedema.