I have been having unilateral h/a that effect my eye. the pain feels like it's behind the one eye. i would get them for months. can a optometrist help?

Possible migraine: Have a pain specialist or neurologist check you for migraines. This word comes from the greek two words: hemi means half, and krainis means head or cranium. That's exactly what a migraine is: pain in half the head.

Not likely: There are a number of possibilities, mostly benign at your age. An optometrist is skilled at fitting glasses and contacts but is not a medical doctor. If you have persistent issues, then see an ophthalmologist.