[footfootfoot]

Spexx,
Thanks for the response, it was helpful. especially the swing analogy. That makes a lot of sense to me because it is in exactly those situations (switching from very close to very far that takes a moment to adjust. I have the same perma clench in my hands after carrying a heavy pail or something.

The problem with thebifocals was that I really didn't need to close up vision correction, he was somewhat over correcting because, like you, he predicted my imminent short arm syndrome.

Walking up a ladder was impossible because the rungs were too far out of the near focus range, tape measure at waist level was O.O.F. so I had to look through the distance lens to see things that I considered up close i.e. <3feet (not a pun, but I'll take the points anyway)

The thing I don't quite understand is that the corrections seem to involve altering focus distance. The doc told me that for vision correction optical infinity is set at 20 feet and beyond.

I'm guessing that if my problem is mainly astigmatism, then as my eyes change focus points, the shape of the cornea is changing and therefore the correction at each focus point will be unique. Since it would be impossible to have infinitely variable focus lenses (not bi and tri focals) you have to hit upon an average correction. Is that why some distances appear sharper than others? Or why can't I be corrected at any and all distances?

Just a guess. Despite decades of being a photographer, I never really learned a whole lot about the physics of lens design.