On Sun, 02 Feb 2003 00:08:55 GMT, RDKirk <rdkirk@mindspring.com> wrote:

>In article <3e365855.8625216@newsstand.cit.cornell.edu>, rpn1

>@cornell.edu says...

>> The idea is so obvious, I'm surprised it has not become

>> standard practice, since there are almost no "downsides",

>> but lotsa "gains" compared with traditional glasses

>> solutions to age-related inability to focus...

>My optometrist suggested it. However, it works best if the differences

>in correction are not that great. If the differences are immense (as in

>my case--my normal clear vision is only a range from 4 to 6 inches

>before my face), that kind of scheme sacrifices binocular vision.

This should not be the case...

Basically with my solution you are alternating

eye corrections among the four bifocal lens

possibilities for near-infinity, 3.5', 2', and

1.5', and the diopter "errors" between these

distance corrections are quite moderate, leaving

a sharp image overlayed by a slightly soft one

(with both eyes used), which in practice looks

sharp... There are other advantages to the

particularities of the set-up (like good distance

vision at the edges and for the ground), described

at www.David-Ruether-Photography.com/articles.html#glasses.