On Tue, 30 Jan 2007 21:31:13 -0700, "Mark A" <nobody@nowhere.com> wrote:
"Robert Martellaro" <robopt@nospam.com> wrote in message
news:eqnsr2toiepn39bpjiveohsn0lknnl6jd3@4ax.com...
Mark,
The vision across the entire lens is compromised to some extent if the
fitting
cross is mis-positioned. The first step is to determine if the FC is
where
it
should be, that the panto is at least twelve degrees, and that the back
vertex
is about 12mm to 13mm (unless specified by the optician). That said, I
would
think that the near and intermediate vision would take a bigger hit if
the
FC is
too low. Let us know what happens.
Robert Martellaro
The reading area did seem quite short on the new lenses, but otherwise the
sharpness was OK. Only the sharpness of the distance area was a problem.
The
above taken together (along with my own FH measurements) led me to believe
that the fitting height was too low.
I had the refraction checked by another OD, and it is OK. The "designated
expert" in the optical shop re-measured my fitting height and determined
that it was 4mm too low (which was obvious to me according to my own
measurements).
Ouch- 4mm is pretty far off.
The original measurement was 22mm on a 39mm high lens
(Autoflex 41 56-19).
I believe that frame style only comes in odd number lens sizes.
It was re-measured to 26mm. I will let you know the
results when the new lens (Zeiss Individual) comes back from Germany in
about 2 weeks.
More like 3 weeks from my experience.
BTW, the guy who originally fitted me was about 50 years old, and he
claimed
that he had personally fitted about 150 pair of Zeiss Individuals (I asked
him).
That's a lot of Individuals considering its been on the market for only
four
years. I don't think I've fit a 100 lenses using free-form technology
since the
Multigressiv came out about 6 years ago.
Because I am fairly tall and taller than most opticians when we are both
sitting down or both standing up, it is often a problem getting a good
fitting height measurement.
I'm six feet but sometimes I have to stand on a stool to get my eyes level
with
my clients eyes, otherwise the FC height will be low. Sounds like that's
what
happened to you. I've also seen some very experienced opticians (and
doctors)
use some old ideas concerning FC heights (too low) and add powers (bumped
for
PALs). Old ideas die hard I guess.
Most people do not complain when they get bad glasses. When I was 16 years
old I went to an ophthalmologist and he did the eye drops before the
refraction, and my glasses were so strong I never wore them. I complained
to
my parents, but no complaint was ever lodged with the MD.
Well, I 've made my share of mistakes too. We are all human, more or less
(Check out my old signature!).
Let me know how you like the Individual. If the Rx was essentially the
same then
improvements in performance will mostly be due to lens design assuming the
old
lenses (Panamics?) were fit well and the frame shape, size, and vertex
distance
were all similar to the new glasses.
Regards,
Robert Martellaro
~~~~~~~~~~~~~~~~~~
Optician/Owner
Roberts Optical
Wauwatosa Wi.
~~~~~~~~~~~~~~~~~~
"Science is a way of trying not to fool yourself."
- Richard Feynman