The opthalmology clinic I visit has recently moved into new offices.  In the
old office refraction for prescribing eyeglasses was done at a distance of
(I assume)  20'.  This was accomplished with the usual
projector/screen/mirror system to achieve the desired eye-to-chart distance,
since the examining room dimension was less than 20'.  The new offices use a
computer-driven LCD screen viewed directly from a distance of about 7 feet.
I asked the techician who was actually doing the refraction if this produced
accurate results and she assured me that it did, since the computer adjusted
the size of the letters in the chart to compensate for the shorter viewing
distance.  Nevertheless, a recent refraction and a re-refraction have both
produced Rx that yielded blurred distance vision, but which are really good
for TV viewing at ~10'.  The optician says the glasses were made to
prescription and the clinic agrees.  Refractions done at the old office were
satisfactory.

I have IOL's in both eyes (since 1990), thus no distance accomodation.
IIRC, shortly after the IOL's were inserted my vision was sharpest at about
6 to 7 feet.  At that time I needed trifocals for distance vision and
reading/computer work.  Over time, my sharpest vision distance has decreased
to about 14".

Is it reasonable to believe that a Rx measured at ~7' will produce good long
distance vision, especially with IOL's?  Is it possible that the Rx measured
at 7' could be mathematically adjusted to provide better long distance
results?

Current Rx:

               SPH            CYL            AXIS            ADD
OD        -1.50            +1.50            173            +2.50
OS        -1.75            +1.00            009            +2.50

Lenses are progressive "Transitions".

Thanks to any and all who reply,

Bob Peyton