Often, a person may discover a subconjunctival hemorrhage on awakening and looking in the mirror. Most spontaneous subconjunctival hemorrhages are first noticed by another person seeing a red spot on your eye. The following can occasionally result in a spontaneous subconjunctival hemorrhage: 1  sneezing, 2  coughing, 3  straining/ vomiting, 4  eye rubbing, 5  trauma (injury), 6  high blood pressure, 7  bleeding disorder, or.