I had the same thing and for me it was a scratched cornea. It became pretty painful. If you have no pain, it is either very small scratch or something that has latched onto the eyeball and the dr. may have to remove it.
I think you should have an eye doctor look at your eye with a magnifier there is no way to tell that something isn't in your eye unless it's done properly. It could be a small piece of anything or it could be a sore on your eyelid, turn your eyelid up and out to see if there is something there and flush your eye with a saline solution for several minutes then see if it feels any better. If not you must go to an eye doctor only for safety sake. Most things caught in our eye will eventually come out with time but then again why take the risk that it be something worse like a blood vessel in your eye that has ruptured or something similar?
Sounds like you scratched your eye. Go see a Dr. for drops and probably will need to wear a patch for a couple of days.
could be hair and you don't always see them try using an eye bath to wash it out with water.