Thanks phg for getting back,... do you have the vise rotated a little towards you off center to get that view, or do you tie straight on with your hands and the hook at eye level?
My avitar is me tying on a Traveler, and using a standard folding table as the work bench. Not ideal, but I've never had a problem doing that. At home, I use a higher bench and the vise is just below eye level, about chin level. No, I tie straight on, I don't rotate the vise unless I just need to.
The hook should be set as high in the jaws of your vise as you can, and still hold it securely. Adjust the width of the jaws to the thickness of the hook, so the vise jaws, when tight, are parallel to each other. This gives you the best hold on the hook with the least strain on the vise jaws.
I'm near sighted, so I don't need magnifiers when I tie, but most people over 40 need some help. Reading glasses are a good choice, but you might also consider a 4x craft magnifier. Lots of women use them for needlework.
Without seeing you tie, I don't know what else to suggest.