I get day long headaches always on the right front of my skull / above my right eye. what could be the cause?

Possible migraine ha: How long has this been going on? If this is a chronic recurrent condition, you might have migraine headaches - which is often throbbing in nature, unilateral, assoc with light sensitivity and nausea. In any case, a recurrent headache should be evaluated by your physician.

Probably eyestrain: More than likely, this is is just eyestrain caused by use.Recurrent headache, however, should always be evaluated.Conditions like glaucoma should also be ruled out by an eye doctor.