Answer by  
                                                                                          Connie45 (1110)
                                                            
                          
                          
                                                          Conjunctivitis may be caused by a ruptured blood vessel in the eye.  Have you injured your eye recently or rubbed it hard?  It can also be caused by a viral or bacterial infection, or by allergies.  For a definitive diagnosis and treatment, see an ophthalmologist.