I've been asked by other trainers in my gym sometimes "What were those eye drill things you were doing with your client? What's that supposed to do?" I do my best to explain how different interactions between the eye muscles, the inner ear, and different structures in the brain can create big changes in the outputs from your nervous system, ultimately having a large effect on your balance, coordinate, strength, mobility, and yes, pain. I'll do brief demos showing the effect on either the flexor or extensor reflexes but sometimes I'll still get a quizzical "Huh", like they're not quite sure how that could work.
So in the interest of simplicity and an awesome demonstration of the adage that "a single picture is worth a thousand words", here is a great video from PBS's SciTech Now (support your local station!) in which we see a patient relieved of a year's worth of pain and dysfunction. If after seeing this, you still have difficulty believing or understanding how eye drills might be able to help your performance in your sport of choice or just life in general, then by all means, go right on back to stretching the frack out of pissed-off, angry structures and submitting your shoulders to another thousand YTWLs...