Whenever i skip i get a really bad pain in the back of my left eye. What could be causing this?

The pain is considerably worse when i skip with both feet together (hopping), it is just bearable when i skip in a running fashion. (pardon my lack of knowledge on what these types of skipping are called, i'm relatively new to the phenomenon!) I cant skip for any more than 5-10 mins without the pain forcing me to stop!