DonM At first you will see the line as being off target. You have to trust the line. And after enough reps, you'll see it correctly. At that point your brain and eyes are becoming re-trained.
I think that's true. When most golfers especially right handed right eye dominant players think they have the putter face square to the intended line it's normally closed and causes pulls. Root cause is putter face must be square to intended line. SeeMore and other mid-shafted kind of putters will display how putter face is aligned to shaft and intended line. Line on ball helps illuminate this issue.
How I putt is use midshaft type (Jerry Korte OG Yes!) like a SeeMore FGP blade play ball mid stance slightly forward no forward press as these kinds of putters have no plumbers neck etc. Lined up square to intended line eyes over ball or just a smidge inside and close left eye (I am right eye dominant). Square putter face to intended line shaft is square with face which when I open both eyes looks slightly open to me but ball rolls straight and no misses left. My miss is left. I learned this from Jerry Korte years back. I do not use a line on ball but a large red dot. This regimen was taught by Jerry to some of the best players in Wisconsin. Steve Stricker is one of Jerry's pupils. If you can get a hold of Jerry's book "The Proof Is in the Putting".....good read.
On edit: One other factor that helps keep my grip light and face square. I use a Garsen Edge putter grip on a Jerry Korte OG Yes! fork blade putter.