magnified vision with polycarb glasses

My RX:
-7.75, -1.00 x 010
-7.50, -1.00 x 175

My old glasses were on a 1 base curve high-index (1.67) in -8.00 and
-8.25. The OD recommended polycarb for the new glasses. The lab made
the new ones 1 base curve on right lens and 2 base curve on left lens.
I finally had to return them because it seemed like I was viewing out
of a magnified fishbowl and I felt like I was walking up a ramp. The OD
was adamant they were correct for me.

I went to another lens lab. They recommended a 1 base curve for both
lenses in a 1.67 high index material. I can see fine out of these
glasses.

My question for future reference: is it the lens material or the base
curve that created the distortions I experienced?
Thanks, Dill

"dill" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed) oups.com...
> My RX:
> -7.75, -1.00 x 010
> -7.50, -1.00 x 175
>
> My old glasses were on a 1 base curve high-index (1.67) in -8.00 and
> -8.25. The OD recommended polycarb for the new glasses. The lab made
> the new ones 1 base curve on right lens and 2 base curve on left lens.
> I finally had to return them because it seemed like I was viewing out
> of a magnified fishbowl and I felt like I was walking up a ramp. The OD
> was adamant they were correct for me.
>
> I went to another lens lab. They recommended a 1 base curve for both
> lenses in a 1.67 high index material. I can see fine out of these
> glasses.
>
> My question for future reference: is it the lens material or the base
> curve that created the distortions I experienced?
> Thanks, Dill

It is the material. Polycarb is crap.

Many ODs on this forum claim that it is extremely rare for patients to
complain about polycarb, but here is proof. Lots of other proof in the
archives of this group.

I'll jump on poly as being bad too, except for low prescriptions, where
the chromatic problems are not as significant. I do use it for kids and
adults at risk for lens impacts when the Rxs are low, especially if
their insurance covers the poly but not trivex and the patient doesn't
want to pay extra (fairly common). Poly is almost as impact resistant
as Trivex, and is thinner and in some Rxs is lighter. It also is "dead
white" meaning there is no color in the lens as there is in Trivex (a
pale greenish).

w.stacy, o.d.

Mark A wrote:

>
>Many ODs on this forum claim that it is extremely rare for patients to
>complain about polycarb, but here is proof. Lots of other proof in the
>archives of this group.
>
>
>
>

The old ones had no cyl at all??? If not, that could be part of the
problem. As far as using the 2 base on the left lens, that was just
wrong and cheap if Robert's guess is right. The stronger lens should be
flatter than the weaker lens, unless you have aniseikonia (which I
seriously doubt). I'd agree, dump the O.D. and don't trust his Rx
either. (having said all that, it's probably the poly causing most of
the problem, but is most likely a combo of several factors).

w.stacy, o.d.

dill wrote:

>My RX:
>-7.75, -1.00 x 010
>-7.50, -1.00 x 175
>
>My old glasses were on a 1 base curve high-index (1.67) in -8.00 and
>-8.25. The OD recommended polycarb for the new glasses. The lab made
>the new ones 1 base curve on right lens and 2 base curve on left lens.
>I finally had to return them because it seemed like I was viewing out
>of a magnified fishbowl and I felt like I was walking up a ramp. The OD
>was adamant they were correct for me.
>
>I went to another lens lab. They recommended a 1 base curve for both
>lenses in a 1.67 high index material. I can see fine out of these
>glasses.
>
>My question for future reference: is it the lens material or the base
>curve that created the distortions I experienced?
>Thanks, Dill
>
>
>

Many thanks to everyone for your feedback. It seems there were several
issues that worked together to create the discomfort, including change
of lens material (the old ones were high index by unknown manufacturer,
the news ones were polycarb by Varilux), different base curves (1.0 to
1.0/2.0), different pupil distances (58 to 57), and new distance rx
(down .5 diopter) to get used to.

For the record, the old rx:
-8.25, -1.00 x 006
-8.00, -1.00 x 175
base curve 1.0, high index lens, PD 31/27 (I measure 55.5 but see
better at 58)

I do not know whether either the new or old lenses were aspheric, but
they didn't look alike at all - the new glasses that gave me trouble
were much more curved on both surfaces while the old lenses were
flatter on both surfaces, even though they have a stronger
prescription. So, to me, they looked like entirely different types of
lenses, although the OD insisted the new ones were right for me. And,
yes, there was a strange color tinge to things.

The one thing the OD did pay attention to was my occupation as a
writer, and he recommended I return to an older rx in the -7 range
versus the -8 range I've been wearing. (Which, for the record, when
they were made, I complained the -8 was too strong for me and made
things tiny up close, but the optician from the large chain that I will
never use again said that I just needed bifocals, which isn't the case.
At any rate, I adapted to my eagle eyes.)

I've learned a lot from this group by reading through the archives. I
think there are different schools of thought about the thicker
polycarbonate lens material. For me, the flatter high index lenses work
best, and now I'll better know what to request.

Thanks again for taking the time to weigh in.
dill

dill wrote:
> My new RX:
> -7.75, -1.00 x 010
> -7.50, -1.00 x 175
1.0 base/2.0 base polycarb, PD 30/27
>
> My old glasses were on a 1 base curve high-index (1.67) in -8.00 and
> -8.25. The OD recommended polycarb for the new glasses. The lab made
> the new ones 1 base curve on right lens and 2 base curve on left lens.
> I finally had to return them because it seemed like I was viewing out
> of a magnified fishbowl and I felt like I was walking up a ramp. The OD
> was adamant they were correct for me.
>
> I went to another lens lab. They recommended a 1 base curve for both
> lenses in a 1.67 high index material. I can see fine out of these
> glasses.
>
> My question for future reference: is it the lens material or the base
> curve that created the distortions I experienced?
> Thanks, Dill

Hmm, the OD said the high index have greater tendancy to stress
fracture, so he ordered the polycarb. The first set had crack at the
top, the second set were broken at the lab, the third set were
scratched at the bottom of both lenses. Maybe he had it backwards in
his own mind?

Robert Martellaro wrote:
> On Mon, 13 Nov 2006 21:04:52 GMT, William Stacy <(E-Mail Removed)> wrote:
>
> Another big concern I have with poly is stress cracks and star cracking around
> the edges. Very disappointing- on both sides of the dispensing table.
>

I don't think a +3 poly would magnify significantly less than a +3
trivex. If I'm wrong, tell me how. and they shouldn't be noticeably
thicker unless the frame has bigger lenses or the lab screwed up and
didn't grind to a thin edge. The differences in thickness AND mag should
be negligible.

w.stacy, o.d.

Anon E. Muss wrote:

>
> I had one patient, TODAY in fact, that I switched back from TRIVEX to
> aspheric polycarbonate.
>
> A 9 year old girl -- about +3.00DS -- she wore aspheric poly for the
> previous 2 or 3 prescriptions until the last exam, when I switched her
> to TRIVEX for the usual reason (better optics). She came in today and
> her mom said she never liked the TRIVEX lenses because her daughter
> felt they magnified her eyes worse than the aspheric poly, and they
> were noticably thicker (n=~1.53 vs n=~1.586).