Do you have any visual disturbances as well?
There could be an inflammatory process going on behind the eye ball..
Get a detailed eye examination done for vision and retinal evaluation also.
If a MRI
or CT scan
is required, your doctor will advise for that too.. just to rule out any pathology..
But don't worry.. it could be a non specific pain also..
Do some warm compresses which can help you in the meanwhile..