Another Progressive Lens Recommendation Request

#13 04-19-2006, 09:58 PM

On Tue, 18 Apr 2006 18:21:07 -0600, "Mark A" <nobody[at]nowhere.com> wrote:

- quote -

> "Robert Martellaro" <robopt[at]nospam.com> wrote in message ..
> > <snip> .
> > Changing to a 42 Abbe lens (1.60 index of refraction) decreases
> > TCA to .13^, much less likely to be noticeable.
> > > Robert Martellaro
> > ~~~~~~~~~~~~~~~~~~
> > Optician/Owner
> > Roberts Optical
> Which brands of 1.60 have an abbe of 42. Does that include Varilux
> (Essilor)?

I'm pretty sure all of the major manufactuers have switched to 42 Abbe 1.60
index. Mitsui Toatsu Chemical supplies most of the industries hi-index
materials. The MR-6 material was the old 1.60 that had an Abbe number of 36, the
latest is MR-8 with an Abbe of 42.

#12 04-19-2006, 02:26 PM

Thanks to everyone for the helpful info and recommendations. I really
appreciate it!

#11 04-19-2006, 12:21 AM

"Robert Martellaro" <robopt[at]nospam.com> wrote in message ..
- quote -

> <snip> .
> Changing to a 42 Abbe lens (1.60 index of refraction) decreases
> TCA to .13^, much less likely to be noticeable.
> Robert Martellaro
> ~~~~~~~~~~~~~~~~~~
> Optician/Owner
> Roberts Optical

Which brands of 1.60 have an abbe of 42. Does that include Varilux
(Essilor)?

#10 04-18-2006, 07:02 PM

On Tue, 18 Apr 2006 12:08:31 -0400, "Ellen" <dontusethis[at]x.com> wrote:

- quote -

> Hi,
> Thanks, yes it does. I was hoping to get a reply from you. I'll try to get
> one of those 2 brands.
> I knew about not getting polycarbonate, but not about higher index, so I'll
> add that to my list.
> Thanks again,
> Ellen
> "Robert Martellaro" <robopt[at]nospam.com> wrote in message
> news:vpv7421dbh8oe506rf83f5ep4rilci4m3d[at]4ax.com...
> > > Gradal Top/Zeiss and Genesis/Shamir are essentially one two for distance
> > peripheral sharpness and comfort. Don't use poly or index over 1.60.
> > > Hope this helps
> > > Robert Martellaro
> > ~~~~~~~~~~~~~~~~~~
> > Optician/Owner
> > Roberts Optical
> > ~~~~~~~~~~~~~~~~~~
> > "If a million people believe a foolish thing, it is still a foolish
> > thing."
> > - Anatole France

Ellen,

The Zeiss lens should be readily available and would be my first choice.

The problem with indexes over 1.60 (one possible exception-Hoya's 1.70) is that
they have higher dispersion (lower abbe numbers) than other materials. If the
lens power is strong enough, there will be some degree of blur as you look away
from the lens center. The amount of blur is determined by the amount of prism
induced (power times distance) divided by the materials Abbe number. The formula
is TCA= P/V where TCA is trans (lateral) chromatic aberration, P is prism, and V
is the material's Abbe number. Jalie has written that .10 prism diopters is
enough to be a concern, and Torgersen says that .16^ is enough to decrease
acuity by one line. That seems to correspond with my personal experience (my Rx
is -4.50) and from feedback from my clients.

However, some folks don't find this to be too much of a problem, depending on
the degree of blurring of course, and may be partially due to how sensitive one
is to these aberrations, and to how often and how far one looks or needs to look
off-axis. Single vision lens wearers can turn their head and avoid the blur for
instance, with multifocal wearers being forced to look down and away from the
lens center 10mm to 15mm (or more) to reach the near focus.

You have stated a preference for the best possible distance off-axis/center
vision and tend to use separate glasses for extended near tasks. In this case I
would look for ways to decrease TCA as well as minimizing oblique astigmatism
and power error. Using your Rx for the right eye (-6.75), a lens with an Abbe of
32 induces .17^of TCA when the gaze is 8mm from the lens center, enough to cause
noticeable blur. Changing to a 42 Abbe lens (1.60 index of refraction) decreases
TCA to .13^, much less likely to be noticeable.

Robert Martellaro
~~~~~~~~~~~~~~~~~~
Optician/Owner
Roberts Optical
~~~~~~~~~~~~~~~~~~
"If a million people believe a foolish thing, it is still a foolish thing."
- Anatole France

#9 04-18-2006, 04:08 PM

Hi,

Thanks, yes it does. I was hoping to get a reply from you. I'll try to get
one of those 2 brands.

I knew about not getting polycarbonate, but not about higher index, so I'll
add that to my list.

Thanks again,

Ellen

"Robert Martellaro" <robopt[at]nospam.com> wrote in message
news:vpv7421dbh8oe506rf83f5ep4rilci4m3d[at]4ax.com...
- quote -

> Gradal Top/Zeiss and Genesis/Shamir are essentially one two for distance
> peripheral sharpness and comfort. Don't use poly or index over 1.60.
> Hope this helps
> Robert Martellaro
> ~~~~~~~~~~~~~~~~~~
> Optician/Owner
> Roberts Optical
> ~~~~~~~~~~~~~~~~~~
> "If a million people believe a foolish thing, it is still a foolish
> thing."
> - Anatole France

#8 04-17-2006, 08:56 PM

On Sat, 15 Apr 2006 16:19:16 -0400, "Ellen" <dontusethis[at]x.com> wrote:

- quote -

> Hi,
> I'm looking for advice on a progressive lens brand.
> I'm 53 years old, have worn progressives fairly successfully about 4 years
> and not so successfully 3 years before that.
> My rx is:
> -6.75 0 0 +2.25
> -4.25 50 40 +2.25
> I don't seem to have much flexibility for where I can focus, and after a lot
> of experimenting, found that I'm much more comfortable if I wear reading
> glasses for any amount of reading, and compter glasses for working at my PC.
> But I like having progressives so I don't have to take off my distance
> glasses for things like reading menus, labels in stores, the display on my
> cellphone, etc.
> I gave up on several pairs of progressives until I tried high-index Varilux
> Comfort, which I've worn ever since. But I wonder if there's something even
> better for distance vision. Could someone who's knowledgeable about the
> better lens brands recommend the one that's best (and has the biggest area)
> for distance? I don't care if the near areas aren't as big, since I never
> use them for serious focusing. The opticians here don't seem as
> knowledgeable as some in this group.
> Thanks in advance.

Gradal Top/Zeiss and Genesis/Shamir are essentially one two for distance
peripheral sharpness and comfort. Don't use poly or index over 1.60.

Hope this helps

Robert Martellaro
~~~~~~~~~~~~~~~~~~
Optician/Owner
Roberts Optical
~~~~~~~~~~~~~~~~~~
"If a million people believe a foolish thing, it is still a foolish thing."
- Anatole France

#7 04-17-2006, 08:15 PM

Is there something else you'd recommend?

I know I have to talk to a good optician, but there aren't very many nearby,
and I'd really like to go in with at least a good idea of something to ask
about that would give me the best distance vision.

Thanks,

Ellen

"William Stacy" <wstacy[at]obase.net> wrote in message
news:%VN0g.16510$tN3.10510[at]newssvr27.news.prodigy.net...
- quote -

> CatmanX wrote:
> > If you have been happy with comfort lenses, then a switch to panamic
> > should do the trick.
> > > There is better peripheral vision and a slightly shorter corridor.
> > Essilor wouldn't release a lens after comfort until they came up with
> > something significantly better - the Panamic was it. All my comfort
> > wearers are now wearing these happily.
> > > dr grant
> > Panamic is on it's way out. Was a dud and will not be available much
> longer.
> w.stacy, o.d.

#6 04-17-2006, 02:49 PM

CatmanX wrote:
- quote -

> If you have been happy with comfort lenses, then a switch to panamic
> should do the trick.
> There is better peripheral vision and a slightly shorter corridor.
> Essilor wouldn't release a lens after comfort until they came up with
> something significantly better - the Panamic was it. All my comfort
> wearers are now wearing these happily.
> dr grant
Panamic is on it's way out. Was a dud and will not be available much

longer.

w.stacy, o.d.

#5 04-16-2006, 10:55 PM

If you have been happy with comfort lenses, then a switch to panamic
should do the trick.

There is better peripheral vision and a slightly shorter corridor.
Essilor wouldn't release a lens after comfort until they came up with
something significantly better - the Panamic was it. All my comfort
wearers are now wearing these happily.

dr grant

#4 04-16-2006, 09:05 PM

Mark A wrote:
- quote -

> Definity is now owned by Essilor. Varilux is just one of
> the brand names owned by Essilor. At least so far, it
> appears that Definity will be marketed under its own
> brand name (not Varilux).
> The Definity splits the add power over the front and back
> surfaces of the lens, and needs to be made on specialized
> equipment designed for that purpose. So, even thought
> they are now owned by Essilor, the are still made on the
> same equipment.

Any thoughts/opinions/feedback on the Physio 360?

-Quick

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