Hi Houston !
I have chronic left occipital headaches from TOS (along with the left face, jaw, throat, and ear thing) Thankfully, no problems with my vision (that I didn't already have

) In the past, I did have a left occipital nerve block, which helped for awhile. Now, the RIGHT PT and chiro are able to help me keep it in check.
I really recommend finding a great PT before you have surgery. I did 2 courses of PT the wrong way in the past......just weights. It made everything so much worse. You need to find one who does myofascial release work. As my PT explains it, adding weights for strength training before losening the fascia to let you get back into proper alignment, is a recipe for disaster.
Good luck !