What Causes Recurring Fever Along With Pain In Eyes?

About every other month my daughter gets a very highpain i fever that last about 3-4 days. She tells me that her eyes and head hurt when she gets it. Other than that, she has no other symptoms. She just turned 3 in December and this has been going on for over a year. Advil usually helps her to function when she gets this fever. What could be causing this to happen so frequently and always the same thing?