Dear Lee,
On balance, it is probably NOT best to watch the putter head in the stroke. Instead, you should appreciate how large the "still spotlight" of vision is when steadily looking only down at the grass directly beneath your face in the setup. When you are content to leave "central" vision on only one location beneath your face, peripheral vision does a good job of tracking the putter head without you having to watch it specifically.
When you don't watch the putter head, the "cone" of vision remains stable in space, and the earth beneath it does not shift and the edges of the cone don't swing about above the ground. Also, when the face and head move in order to follow the putter head as it swings back, the inner ear fluids slosh about, and this degrades the sense of the body location in space. Done with consistent movement and rhythm, you CAN get used to this so that it doesn't hurt the sense of spatial awareness much, but you need consistency.
You can "divide" attention a little between central and peripheral WITHOUT using central vision to follow the motion of the putter head in the backstroke. This means you aim your vision straight down at the ground but don't pay attention to what is at the end of the line of sight. Your vision has a "blank stare" aspect that frees up your attention to what is going on in the periphery, but you don't "go there" with your eyes or your face.
Also keeping your face aimed straight down helps you sense the physical movement of the stroke with your attention.
Should you employ your attention like any of this in the making of the stroke, whether "paying attention" to a spot on the ground, or "paying attention" to the periphery while aiming the vision blankly straight down, or "paying attention" to the feeling of the stroke while aiming the face and vision blankly straight down? Well, ultimately, probably not, but it doesn't hurt performance near as much as certain academic researchers and golf psych frequently profess.
And watching the putter head in the backstroke is not necessarily the worst thing in the world either, unless you are a perfectionist, which IS the worst thing in the world for putting. So if your reason for watching the putter head is because you are WORRIED about being perfect in your stroke, then yes, by all means, stop watching it. But more fundamentally, stop worrying and stop trying to be perfect all the time. You will actually have much more successful putting (better results each putt, better results far more frequently) if you relax and just accept your best as "good enough".
Cheers!
Geoff Mangum
Putting Coach and Theorist
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