I'm struggling with my low outside zone also and yesterday I took advice I read on here and tracked the ball so that I could read the log on the catcher's glove. It made me realize that I am, in fact, shifting my eyes back up to catch the batter's swing. In fact, I think I verbalized a strike that the batter offered at because my eyes were focused on the ball and catcher's glove.
So, how do I see both the ball all the way into the glove AND the batter's swing?!
Nic