Glad you found the source of your problems before they became big ones.
Would there be an advantage to getting custom glasses for using your computer instead of just using the ones you found?

My dad always had headaches back when he was in school. As it turned out, one eye was only slightly off-focus from the other. Combined with the brain's focusing operations (focus with one eye, then focus with the other eye, oh hey, the other one's out of focus now, ad infinitum), he had almost constant headaches.
(he almost didn't get glasses, either, as the prescription was too slight for most optometrists)