I have the same issue and going for the vision therapy. Already went for 9 sessions and didn't see much improvement except I feel better immediately afterwards for 3-4 hours and next day all back to crap. Vision therapists I go to are very good. Can't complain.

It is a brain thing. But my brain seems to be rigid and refuses to learn. Also my Nero-Optometrist mentioned there is a chance it can be even before head injury and now it got worse since after TBI it gave up for compensating.

I will be continuing for sure. That is something you definitely can look into and some has good success in eliminating headaches.