Zeiss GT2 vs. Varilux Definity

[optigrrl]

RX: OD +2.00 -.50 X 85
OS +1.75 -.25 X 105
ADD +2.25

Lenses are the same shape and both fit at 20 hi.
Material: Poly

Dad (pt.) previously wore the Sola One HD in 1.67 and was quite happy. Same shape, same seg.

First pair tried on was the Definity. I noticed him looking for the reading area which prompted me to triple-check my measurements. They were bang-on, so we proceeded.

For near vision: Dad felt that overall the Definity had a wider viewing area at near than the GT2, but was instantly able to find the optimum viewing area in the GT2 whereas he had to "search it out" at first in the Definity.

Intermediate: Again, a little wider in the Definity than the GT2 but had to tilt his head up in the Definity for best VA. The GT2 allowed a more natural head angle at his computer as well as more vertical - he could move head up or down a little and not lose clarity - so sitting upright or slouching did not affect head-tilt comfort. The GT2 was more "forgiving" of posture.

Distance: Here is where it gets interesting. He felt that the GT2 had significantly more VA in the lens both vertically and horizontally. To be specific, I had him focus on a target with the Definity while checking the segs and see his best head position for distance VA. Looking straight ahead comfortably was what worked, but I had him try tilting his head up and down until the object lost crispness. So on his own he repeats this with the GT2 and tells me that he had clarity both looking ahead naturally as well as tilting his head down and looking through the very top of the lens. He said that the Definity lost focus as he tilted his head downwards.

Walking down a flight of stairs he felt no significant difference in comfort between the two.

SUMMARY:

While the Definity has a wider near and intermediate zone the patient felt that he had to raise his chin higher than normal in order to obtain best VA. Pt. appreciated the greater distance viewable lens area in the GT2, especially for driving. Pt. also liked the "instant" ability to find NV acuity in the GT2 lens even though he liked the wider viewing area of the Definity at NV and intermediate.

When asked if he had to give one up, which one would he choose - he answered: "Now why do I have to do that?"

I guess they both have their advantages! (The advantage of having an optician for a daughter, too!)

[Chul]

Hi optigrrl.

I have some questions. Do you mean the Definity is J&J's PAL? What is GT2?

[optigrrl]

The Definity was (I think) J & J's first attempt at launching a PAL. It has a fixed +.75 add of power on the front of the design and the remaining add power is ground in the back. This was to create the "keyhole" affect and widen the viewing area at near.

They went head-to-head in a marketing campaign against Varilux on the east coast...and lost to the master. So - Essilor canabilized (bought) the Definity. Now it's being marketed here in the west.

First rollout - it was being marketed to us opticians for the advantages of the keyhole effect and it's benefits. The second campaign I went to they were selling it as "The Golfer's PAL", and that it was improved for vertical declines (going down stairs). Which makes sense - given my dad's experience. This is a great thing for elderly people who may not have the best balance. If they have to crank their chins down to navigate a stariwell or escalator it can have an adverse effect on their posture. OR - they don't realize the change in depth perception without putting their head down and miss a step.

The GT2 is the new version of the Zeiss Gradal Top. The Gradal Top has a very long channel of progression and even though Zeiss says it can be fit at 18 hi, I wouldn't ever think of fitting it below 22 because you lose the reading. (IMHO)

The GT2 has an improved and shorter channel and truly can be fit at 18 hi while still giving the patient ample reading. It still has the variable inset technology (see Darryl M. on this) but now opticians can offer this PAL in smaller frames than it's predecessor, the Gradal Top.

Hope this helps!