Distance vision area on a progressive lens

Does the distance vision on a typical progressive lens (+4.75 -1.75 x90 with
+2.25 add in my example) maintain the same power all the way up to the top
of the lens? Assume a frame that is 40mm high with a fitting height of
about 24mm. Lens is Zeiss Individual.

On my new lenses, the distance vision appears a bit less sharp at the top of
the frame. I am not sure if that is because my Rx is too weak in the
distance area, or if that is normal. I am also not sure if it is because my
best distance vision is actually using part of the intermediate corridor and
picking up a bit more strength to achieve my best distance vision.

"Robert Martellaro" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> Mark,
>
> If you look at a distance object the vision should blur slightly if you
> raise or
> lower your chin, more so if you raise your chin. That's with a relaxed
> standing
> posture looking at an eye level object beyond twenty feet.
>
>>I am also not sure if it is because my
>>best distance vision is actually using part of the intermediate corridor
>>and
>>picking up a bit more strength to achieve my best distance vision.
>
> That might happen if the object is closer, the fitting cross too low (the
> Zeiss
> Individual is optimized for Rx and "position of wear"- FC must be central
> pupil
> with the panto, face form, and back vertex distance specified if they are
> atypical), or if the Rx is slightly under-plused for your age and viewing
> habits.
>
> Robert Martellaro

What I mean is that when I raise the frame up about 3 mm (keeping my head
straight), the distance is clear. I did this to see if the fitting height
was too low. But I cannot tell if the reason for sharper distance vision
when the frame is raised 3 mm is because of the fitting height is measured
wrong, or because the Rx is wrong (and I am picking up some extra needed
power in the intermediate area).

I am getting a recheck of the Rx, but I was wondering if I should be able
see clearly out of the distance portion, even if the fitting height is 3 mm
too low.

"Robert Martellaro" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> 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). The original measurement was 22mm on a 39mm high lens
(Autoflex 41 56-19). 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.

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).

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.

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.

"Robert Martellaro" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> On Tue, 30 Jan 2007 21:31:13 -0700, "Mark A" <(E-Mail Removed)> wrote:
>
>>"Robert Martellaro" <(E-Mail Removed)> wrote in message
>>news:(E-Mail Removed). ..
>>> 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

"Robert Martellaro" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
>>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.

You are correct. My new frame is the Autoflex 47 56-19. The height is 39mm
(40.4 according to manufacturer). My old frames are Autoflex 41.

> More like 3 weeks from my experience.

My first pair of Zeiss Individual came back in 11 days (about a week ago).

> 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

The technician who measured my remake said that he also changed the
pantoscopic angle, so that may also be somewhat of a factor. I don't know
what the original PA was, nor do I recall what he changed it to.

"Robert Martellaro" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> Then Zeiss must have shifted production to their US facilities. I'll check
> it
> out. Heretofore its been 3 weeks minimum to Germany and back, even with a
> fast
> track through customs. The ID and Multigresiv still take 3+ weeks.
>
> Robert Martellaro

The optical shop said it goes to Germany. Either they don't really know, or
it is just the right time of year for quicker turnaround. Or maybe the don't
ship everyday, and I just hit the right time of week. I checked the
etchings, and it was a Zeiss Individual 1.6.