Pretty sure it was the contact lens that caused the headache today. 
I was trying the stronger prescription today just to see how my eyes adjusted with it, and I guess it got a bit irritated somewhere.
Thankfully I brought the lesser prescription and switched to them after a couple of hours, but the headache refused to flee. Took some meds of Excedrin and advil and such but headache prevailed.
Managed to have it go away for a little bit after I took a nap, but hiking back up the hill after a walk around the block brought it back for a bit. *exhales*