zeiss gt2

**Multicoat** · 07-15-2008, 05:58 AM

could anyone explain the specifics of the zeiss gt2? i was under the impression this was a free form generated back surafce. After reading the lensguru digitallly sufaced chart the back is "standard." standard meaning it is just a standard atoric back curve?

can anyone point me in the direction on where i can find more technical information on the zeiss gt2

cheers

au · 07-15-2008, 06:22 AM

Check this up,

http://www.zeiss.com/lenses

hope this help !

:cheers:

RT · 07-16-2008, 06:37 AM

standard meaning it is just a standard atoric back curve?

No, standard meaning it is just a TORIC back curve.

**Darryl Meister** · 07-27-2008, 08:51 PM

All semi-finished progressive lenses made by ZEISS utilize "free-form" or "direct" surfacing of the lens molds, and have for many years now. GT2 by ZEISS is a traditional, semi-finished lens, however, which represents the most technologically advanced lens design in the ZEISS portfolio of semi-finished lenses.

Individual is a free-form progressive lens that is customized for each wearer, on the other hand, which represents the most technologically advanced lens design currently offered by ZEISS. Like all of Carl Zeiss Vision's free-form progressive lenses, Individual is directly surfaced by the laboratory.

As always, you can learn more about these products at the Carl Zeiss Vision website.

**rdcoach5** · 08-14-2008, 07:17 PM

Darryl, we know you have all the math and you need it to design lenses, but actually wearing a lens is the proof to me. I have tried GT2 , Unique, Physio ,Image, Creation and Sola HDV all in the same Rx and same frame. My favorite lens is the GT2 because I do a lot of near and intermediate. Was this lens designed to be better at this working range? By the way, the HDV is pretty awesome for dist, just not quite as good as GT2 for near. Any other feedback on these lenses?

**Darryl Meister** · 08-16-2008, 11:47 AM

My favorite lens is the GT2 because I do a lot of near and intermediate. Was this lens designed to be better at this working range?

Yes, actually one of the biggest lens design changes incorporated in GT2 after Gradal Top was a higher, wider near zone. After the merger between ZEISS and SOLA, our lens designers immediately began sharing their research on progressive lens design. ZEISS lens designers have always placed slightly more emphasis on distance vision utility, while SOLA lens designers have recently began placing more emphasis on near vision utility with designs such as SOLAMAX and SOLAOne. GT2 represents the first progressive lens that was sort of a "mutual effort" between both sides sides of the new organization.

We had been doing a lot of research using head-tracking devices over the years, and we now have a pretty sizable database of typical eye rotations during intermediate and near viewing tasks. These data were used to determine the corridor length for the GT2 lens design.

By the way, the HDV is pretty awesome for dist, just not quite as good as GT2 for near

Honestly, I haven't really received any negative feedback regarding SOLA HDV, and I wouldn't necessarily expect to, since the lens design platform has already worked very well for us in similar progressive lens designs. Like both SOLAOne and SOLAMAX, SOLA HDV has a unique near zone shape that widens higher up in the progressive corridor of the lens, so I would normally expect the lens to perform quite well at near. Of course, SOLA HDV also offers have a variable corridor length that is matched to the frame size, although we place a limit on the maximum length of the corridor in order to ensure physiologically comfortable reading utility.

**optigrrl** · 08-16-2008, 05:36 PM

I had my father compare the GT2, Definity and the Sola HDV since I don't have a visual correction and he felt that of the three, the HDV was the best for "all around" use.

He liked all three, but felt that for reading the GT2 had instant add vs. the Definity and he had to travel further down the lens to get to a wider reading area. He preferred the Definity for computer work, over the GT2.

On a side note, his favourite lenses are the Hoya iD's over all the others I have made for him.

He's a +2.25, minimal cyl and a +2.50 add.

**allanon** · 08-16-2008, 11:15 PM

Not sure what your experiences are, but we had an 8-12% non-adapt rate with the GT2. Soft on top, hard below the belt. My guess is these were patients moved out of Hoya's Wide and ECP.

**Fezz** · 08-16-2008, 11:25 PM

Originally Posted by allanon

Not sure what your experiences are, but we had an 8-12% non-adapt rate with the GT2. Soft on top, hard below the belt. My guess is these were patients moved out of Hoya's Wide and ECP.

I had similar experiences. We were BUMMED out because our non-adapt numbers are really low!

**optigrrl** · 08-17-2008, 03:22 AM

Originally Posted by allanon

Not sure what your experiences are, but we had an 8-12% non-adapt rate with the GT2. Soft on top, hard below the belt. My guess is these were patients moved out of Hoya's Wide and ECP.

:D Moving? Why move????

**Darryl Meister** · 08-17-2008, 11:04 AM

Not sure what your experiences are, but we had an 8-12% non-adapt rate with the GT2. Soft on top, hard below the belt

That is a bit odd. We had a clinical study done last year among four different practices with 69 subjects, and the acceptance rate was at least 95%...