Hi Fran. I've enjoyed your posts over the years and still remember much of what you showed me in the one lesson I took from you years ago. Unfortunately it is not easy for me to make it into the city that often.
I wanted to say that I have been working diligently on straightening out my stroke at all speed levels and am glad to say I'm about there now. So the comments I make here are not uninformed on my part nor are they meant to be controversial. It just is what it is.
I shoot left-handed and am left eye dominant. My "default" eye position is having the cue under the inside corner of the left eye. After years of experimenting, I have found that my best results come from positioning the cue under my non-dominant right eye. I have no eye issues causing that. In fact my left eye is stronger, naturally. I did have LASIK about 5 years ago, so I'm pretty good with both eyes now.
Without writing a novel, let me just say that when I get down on a shot without thinking about what I am doing, and when the shot looks right, the video camera staring back at me shows that I now naturally put the cue under my non-dominant eye (inside corner).
I guess one of my mantras based on this "research" is that just because your dominant eye is over the cue, that does not mean you can achieve a straight stroke from that head position. I would even hazard a guess that most people who think they have a straight stroke, do not in reality. To me, a stroke is straight when it still looks straight under slow motion video. Some have commented that I overdo the straight stroke thing, but I have proven with some simple test shots that very small stroke errors do have negative consequences.