What Causes Recurring Pain Behind The Eye Along With Headaches?

I have been experiencing severe eye pain behind my right eye for months now. It subsides eventually but always comes back. I have seen an opthamologist and they claimed they couldn t see anything abnormal. It has become extremely painful recently especially this morning upon waking. It feels like it s behind my eye in the socket and throbs and it radiates to the upper side of my faces sometimes causing headaches. My Dr.sent me to the opthamologist so I still don t have any answers as to what could be causing this pain. I hope someone can give me some answers. Thanks...