Blood in eye. Blood over the white part of the eye is called subconj heme-- this will resolve in 2-4 weeks. If it does not, or if is inside the eye, then consult your local ophthalmologist.
Nothing or lots. If by blood in your eye you mean that it looks blood red, but no pain or discharge, this is just like a bruise, and will clear on its own with time. If you have blood inside your eye from bleeding from medical issues, then you need to see an ophthalmologist soon to determine the cause and seek treatment if needed.