# Optical Forums > Progressive Lens Discussion Forum >  Problems with Zeiss Gradal Brevity and GT2s compared to Nikon

## roger1

I'm only peripherally involved in the eye-care profession so I'm not sure if my query will get answered. (I'm an electrical engineer involved in a startup company, eSight Corporation, working on some very exciting electronic eye-wear for the severly visually impaired.) My question here though relates to my own prescription and problems.


OD: -1.25 -0.5 002
OS: -1.75 -0.75 177
Add: +2.25, +2.25 (note I can read fine without any glasses on)

Both my new and old glasses have about 30mm high lenses.

I have been using Nikon progressives for 4 years now (same distance prescription as above but Add might have been 1 to 1.5 or so - don't have the old prescription handy). I recently got new progressives for my new prescription. I did NOT get them from my Optometrist but regret this now. I was told Nikons would be $900 but I could get Zeiss for $550! I went with Zeiss and was given some Gradal Brevities but I found them to have very poor off-axis performance (really for all distance, medium and near). The medium distance all seemed fuzzy too. I stood 20ft from an eye-chart on-axis and then two paces to right and left, and looked at the chart by moving my eyes not my head and my vision was MUCH worse than on-axis. This was not the case with my old Nikon's. I also noticed that my new frames and lenses had more curvature than my old ones so was wondering if that was causing the lateral distortion. I went back and discussed the problems and was then outfitted with some GT2s and with less lens curvature. I still am very unhappy with these. The off-axis performance is terrible and I get motion sickness. I have to swivel my head all the time and hunt for focus. I use two computer monitors at work and one is at right angles to the other (due to my desk design, docking station, etc) and I can no longer use the monitor on the side without totally swiveling and tilting my head). This was NOT the case with my old Nikon's. I also find that even for the mid-range I sometimes need to tilt my head down and look more through the top of the lens, as if the mid-range has already got too much Add in it.

As an engineer of course, I'm trying to figure out the reason for the lens design and problems. I took the lenses off and look at some printed circles and I can see tons of distortion as I move the lens over the circles. They go from circular to egg-shaped tilted on one axis and then the other, just in a space of a couple of cm movement. The lateral distortion is way less with my Nikon's. Why are lenses designed like this? Why not keep the prescription constant over the horizontal? Is this what old bifocals and trifocals (do tri-focals exist) do? Would I be better off with something like that instead of these more complex progressive lens designs?

The only problem with my old Nikon's was that reading was becoming difficult for small text and I would either take them off or look below the lens. I just want the performance of my old Nikon's with the reading fixed. Is this not possible?

I'm surprised I'm having problems with the GT2s and I see on this forum that supposedly most of your customers are happy with them. I consider them totally unusable at the moment though.

Do you think the problem is due to my new prescription and increased Add, or is there something fundamentally different in the Nikon vs Zeiss progressive design, such that it makes the Zeiss lenses unusable for me?

I'm also wondering if I'd be better off just with a distance prescription and removing the glasses for reading and for using a laptop.

I will of course go back to the store but I'd like some more information first. I'm also not sure what happens in these scenarios. Who bears the costs of all the re-builds? The customer, the store, or the lens company?

Thanks, ..Roger

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## roger1

BTW, I did look at the technical article on "The Optics of Progressives" http://www.opticampus.com/cecourse.p...essive_lenses/ and I see that higher ADDs result in shorter corridors and increased astigmatism and less mid-range utility. However, surely there are people with higher ADDs than mine successfully using Progressives.

I'd really like to know if the issue is my changed ADDs prescription, or the Zeiss vs Nikon design.

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## Robert Martellaro

> I just want the performance of my old Nikon's with the reading fixed. Is this not possible?


Short answer, no.




> Do you think the problem is due to my new prescription and increased Add


Right. 




> I'm also wondering if I'd be better off just with a distance prescription and removing the glasses for reading and for using a laptop.


That's one possible solution. For most folks it would be best to have a dedicated pair for intermediate/near work. The distance pair could be single vision, or progressive that has a design that is heavily biased towards the distance vision. 

You need to find an optician who understands the situation. Have them read this, and if they nod they're head in approval then you're probably good to go. If you get a blank stare and/or a promise that using a better more expensive lens will fix everything then walk away. 

I would also recommend wearing the second set of lenses for 10 days or so (sometimes much longer). It takes that long for the brain to adapt to the blur zones and boundaries. Make sure that they're fitting close to the eyes, and that the fitting point is accurately positioned. Get a second opinion from a skilled and experienced optician. This pair might suffice has a general purpose pair. It's likely that you'll need a separate pair for the dual monitors though.

Hope this helps,

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## kat

I agree that with your higher add you might be better served with a computer style lens for your close to mid-range viewing. If you get a blank look from your optician, keep looking for one that understands what your special needs are.

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## roger1

Thanks Robert.

I guess I should double-check the prescription too, especially the Add. I think perhaps it is over-kill and I could back off on the Add a bit, if this will improve the distance and mid vision.

Two sets of glasses is an interesting option too.

At the same time I'm experimenting with mono vision and multi-focal contacts.

It seems to me the real solution for all of this is a surgical or chemical way to fix presbyopia and then laser eye surgery for the myopia!

I'll go and discuss it with optical store and see what can be done. Perhaps there are some tweaks in corridor, etc that could be made.

Finally, yes I'll give my brain time to adjust before going back.

..Roger

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## OCP

> I'm only peripherally involved in the eye-care profession so I'm not sure if my query will get answered. (I'm an electrical engineer involved in a startup company, eSight Corporation, working on some very exciting electronic eye-wear for the severly visually impaired.) My question here though relates to my own prescription and problems.
> 
> 
> OD: -1.25 -0.5 002
> OS: -1.75 -0.75 177
> Add: +2.25, +2.25 (note I can read fine without any glasses on)
> 
> Both my new and old glasses have about 30mm high lenses.
> 
> ...


Well you dont tell us the name of your Nikon lenses, but I find the abberations in Brevity quite noticeable of axis, so this could actually be one of the reasons for your issues. I agree that the large increasing of addition could be a reason as well.
The distance vision in GT2 should be much better of axis.

Mike

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## roger1

yes the GT2 distance off-axis does seem better than the Brevity was.

I'm not sure I have the full name of the Nikon's. My receipt says NIkon HCC Nikon i (1.6).

One thing I notice with my prescription/eyes is that I don't really need a "mid-range" prescription. I can see my computer monitor and read 12 point or 10 point font (barely) on the monitor (at about 1M) with my distance prescription. I can read bulletin boards, read stuff on shelves at the grocery store, etc, all with my distance prescription. If I switch to a laptop that is closer then I can use it fine without any glasses and ditto for reading anything. Trouble is I don't want to have to take glasses off when I'm in my office and moving from my monitor to trying to read some paper on my desk. Also if I'm driving I want to be able to pick up my phone and be able to see who's calling or pick some music (although it's getting illegal to do now without handsfree!) without removing my glasses. So with progressives it's better in that I can just keep my glasses on but this comes at the expense of very narrow vision as I scan through the mid-range and down to the reading.

Despite my technical education, I don't really understand the physics of optics and why one has to have the astigmatism and blur at the sides of the useful corridor. Is this all due to trying to avoid having visible lines on the lenses as one goes between the distance and near prescriptions, and trying to grind/manufactuer it fall from a single piece of glass/plastic?

Would my particular prescription be better served with a standard old-fashioned bi-focal (or just a shallow pair of glasses that I look below for near) or would I find the sudden transition from far to near disturbing?

..Roger

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## Robert Martellaro

> Despite my technical education, I don't really understand the physics of optics and why one has to have the astigmatism and blur at the sides of the useful corridor. Is this all due to trying to avoid having visible lines on the lenses as one goes between the distance and near prescriptions, and trying to grind/manufactuer it fall from a single piece of glass/plastic?


http://journals.lww.com/optvissci/Fu...heorem.14.aspx




> Would my particular prescription be better served with a standard old-fashioned bi-focal (or just a shallow pair of glasses that I look below for near) or would I find the sudden transition from far to near disturbing?
> 
> ..Roger


Disturbing, aggravating, probably. No intermediate vision. Flip side is outstanding distance and near vision with wide fields of view. Your next step is to find experienced optical profesionals who can sort this out for you.

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## rdcoach5

> http://journals.lww.com/optvissci/Fu...heorem.14.aspx
> 
> Disturbing, aggravating, probably. No intermediate vision. Flip side is outstanding distance and near vision with wide fields of view. Your next step is to find experienced optical profesionals who can sort this out for you.


No matter what you do for some individuals, progessives don't satisfy. I said satisfy because that is the crux of the issue.Progressives are always going to have a smaller zone of int or near. Some people just cannot or choose not to adjust to the progressive zone that 95 % of us do. I lose patience with those who tell me they have tilt their head 1 degree down to see an object just below eye level but tilt slightly up for computer. THAT"S the perfect fit! ADJUST ! I know, in this case it was the perennial problem, the emmetrope. Venting, I could vent more but my blood pressure is just going down.

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## braheem24

I'm shocked you're getting answers, there are some MAJOR basic questions that need to be answered before we can troubleshoot, for all we know you have a 0.9 ct with a wave in your lenses.



EDIT:

I'll give you a crazy guess that will still make sense with the info provided...

add a -0.25 ou in the distance this will alleviate a little of the peripheral distortion in yhe distance

 next,

reduce the reading to a +2.00 the will widen the corridor in the near and still give you the +1.75 you naturally prefer.

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## YrahG

> I'm shocked you're getting answers, there are some MAJOR basic questions that need to be answered before we can troubleshoot, for all we know you have a 0.9 ct with a wave in your lenses.
> 
> 
> 
> EDIT:
> 
> I'll give you a crazy guess that will still make sense with the info provided...
> 
> add a -0.25 ou in the distance this will alleviate a little of the peripheral distortion in yhe distance
> ...


I agree a lot of holes in the story, but the guy went from a 1.00 to 1.50 to an add of 2.25; almost a full diopter and this guy is an engineer.  No offense roger1, but your profession proves to be the most chalenging to fit mostly due to your knowledge in physics and lack of knowledge in optics.  Of course it doesn't help that a majority of professionals that would do the actual fitting and picking of lenses will probably still know less then you about optics.

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## Robert Martellaro

> I'm shocked you're getting answers, there are some MAJOR 
> basic questions that need to be answered before we can troubleshoot, for all we 
> know you have a 0.9 ct with a wave in your lenses.


That's one of the reasons I posted this _three_ times. 




> You need to find an optician who understands the situation.





> Get a second opinion from a skilled and 
> experienced optician.





> Your next step is to find experienced optical 
> professionals who can sort this out for you.





> I'll give you a crazy guess that will still make sense with the info provided...
> 
> add a -0.25 ou in the distance this will alleviate a little of the peripheral distortion in yhe distance


But now he won't be able to see the monitor. 




> One thing I notice with my prescription/eyes is that I don't really need a "mid-range" prescription. I can see my computer monitor and read 12 point or 10 point font (barely) on the monitor (at about 1M) with my distance prescription. I can read bulletin boards, read stuff on shelves at the grocery store, etc, all with my distance prescription.





> next,
> 
> reduce the reading to a +2.00 the will widen the corridor in the near and still give you the +1.75 you naturally prefer.


So you bump the distance -.25 and cut the Add +.25. The near is now down +.50 from the original Rx. 




> The only problem with my old Nikon's was that reading was becoming difficult for small text and I would either take them off or look below the lens. I just want the performance of my old Nikon's with the reading fixed. Is this not possible?


Your solution creates one problem and ignores an existing problem.




> No offense roger1, but your profession proves to be the most chalenging to fit mostly due to your knowledge in physics and lack of knowledge in optics.


I like working with engineers because of their "perfect is good enough" mentality. 




> Of course it doesn't help that a majority of professionals that would do the actual fitting and picking of lenses will probably still know less then you about optics.


Therein lies the problem.

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## roger1

Thanks for all the replies. Not sure if I'm being criticized or not, here for being an engineer! I think the engineering background just makes me more curious to understand the reasons and not accept "mediocrity" so easily until it's proven to me that's the best I can get. Of course, it might mean I think know more than I do, but I'm aware of that at least.

I'm not against trying to adapt to PALs as someone suggested. I already did that with my previous Nikon progressives and it took about a week, but now with the new ones I'm finding it really hard as the distortion and swim is much worse, and the required head motion is very large. As an example, if I'm driving and look to the side mirror, stuff is out of focus, unless I totally tilt my head down and touch my chin to my shoulder.

I will go back to the Optician, and if I have to I will go back to my Optometrist. I will do that next week after giving these new lenses a fighting chance, but for now I thought a few posts on this board would make me more informed.

I have now confirmed that my previous prescription had an add of +1.5 (at least that was written on the prescription and I have no reason to doubt that was how the Nikon's were made). My new prescription is +2.25 on both eyes I might add, when I'm not sure this is actually required on both eyes. From logic that I can read fine without my glasses (esp right eye), it seems like I shouldn't need +2.25 on my right eye if we are starting out with a -1.25/cyl-0.5 in the right eye. Is there any problem with making the add different for right and left eyes with a PAL?

I think that perhaps the fitting is not great, and that the mid-range starts too high on the lens. As I said, I think I have very little need for the mid-range. My monitor is still in focus with my distance prescription. Is it possible that the Nikon i had a more rapid progression to the near field. Is this called a short corridor? Where can I find the optical profile of the Nikon i, circa 2006 lens, or does the "i" not infer enough information about the type of Nikon I had?

Are there "better" progressives now than the Zeiss GT2 that give wider field of view and less peripheral distortion. i.e. things with "sandwiched" lenses or whatever. I'd appreciate a bit of non-marketing explanation of the various types of top-of-the-line PALs.

Thanks, ..Roger

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## Robert Martellaro

> Thanks for all the replies. Not sure if I'm being criticized or not, here for being an engineer! I think the engineering background just makes me more curious to understand the reasons and not accept "mediocrity" so easily until it's proven to me that's the best I can get. Of course, it might mean I think know more than I do, but I'm aware of that at least.


I wasn't being facetious- I really do enjoy working with clients who take an interest in the science of ophthalmic optics. It doesn't matter if you're an engineer or a homemaker- it takes time to get this right the first time. 




> I'm not against trying to adapt to PALs as someone suggested. I already did that with my previous Nikon progressives and it took about a week, but now with the new ones I'm finding it really hard as the distortion and swim is much worse, and the required head motion is very large. As an example, if I'm driving and look to the side mirror, stuff is out of focus, unless I totally tilt my head down and touch my chin to my shoulder.


That's going to happen with all PALs at this level of presbyopia, some lenses more than others. It will probably go away with neural adaptation. 




> I will go back to the Optician, and if I have to I will go back to my Optometrist. I will do that next week after giving these new lenses a fighting chance, but for now I thought a few posts on this board would make me more informed.


That's fine, but at some point you need to hand this off to a professional who can narrow the focus somewhat. Even so, it would take me 45 to 90 minutes of Q & A and trial framing before I would feel confident that I had the right soulution for your specific Rx and visual needs.




> I have now confirmed that my previous prescription had an add of +1.5 (at least that was written on the prescription and I have no reason to doubt that was how the Nikon's were made). My new prescription is +2.25 on both eyes I might add, when I'm not sure this is actually required on both eyes. From logic that I can read fine without my glasses (esp right eye), it seems like I shouldn't need +2.25 on my right eye if we are starting out with a -1.25/cyl-0.5 in the right eye. Is there any problem with making the add different for right and left eyes with a PAL?


The Add power needs to be the same for both eyes. 




> I think that perhaps the fitting is not great, and that the mid-range starts too high on the lens. As I said, I think I have very little need for the mid-range. My monitor is still in focus with my distance prescription. Is it possible that the Nikon i had a more rapid progression to the near field. Is this called a short corridor? Where can I find the optical profile of the Nikon i, circa 2006 lens, or does the "i" not infer enough information about the type of Nikon I had?


What was best for you 4 years ago is not relevant to your present situation.




> Are there "better" progressives now than the Zeiss GT2 that give wider field of view and less peripheral distortion. i.e. things with "sandwiched" lenses or whatever. I'd appreciate a bit of non-marketing explanation of the various types of top-of-the-line PALs.
> 
> Thanks, ..Roger


It's not the quality of the lens per se, but the accuracy and optimizing of the lens position, choosing the correct lens or lenses, the Rx, and any modification of the Rx. 

Try the Canadian discussion forum for an optician recommendation for your area.

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## braheem24

> That's one of the reasons I posted this _three_ times.


You should hopefully have 2 patients coming in sometime next year telling you how while on vacation in Florida an optician told them one of the best opticians in the country is in thier backyard in Wisconsin.  

That being said, I'm still unsure offering any solutions without all the facts is not just further complicating the issue. 

Roger1,  for the record I too enjoy working with Engineers who take an interest in optics but I dont like giving ammunition to further confuse a probably simple situation.  

I'm sure there's a simple answer in the hands of the right optician, unfortunatly coming into an optical with hypotheticals may further confuse the situation.

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## Robert Martellaro

> You should hopefully have 2 patients coming in sometime next year telling you how while on vacation in Florida an optician told them one of the best opticians in the country is in thier backyard in Wisconsin.


Thanks. I'll treat them like family. Watch for a PM.

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## Barry Santini

> Thanks. I'll treat them like family. Watch for a PM.


Actually, in view of the above, I'd like to formally float an idea I've been tossing around:

Over the last few months, I've received several calls from prospective clients who wanted to travel from quite a distance to me for an advanced eyewear fitting.  Some have lurked here on optiboard. Some were referred by other optiboarders.  I haven't seen any of them.  But these situations did point up the opportunity to form some type of qualified-referral network amongst those ECPs who consistently demonstrate adherence to high standards of skill and care.

Whose ready to help me flesh out this idea, for the benefit of all, including the prospective public who is *not* motivated strictly by price/insurance for their eyewear?

Help!

Barry

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## braheem24

Barry you have a +8.00 kid coming in to see you sometime this year hopefully, I sent his family to info for the 2 ODs you recommended in the area last month.

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## Barry Santini

Hugs and kisses, braheem24

Barry

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## Robert Martellaro

> Actually, in view of the above, I'd like to formally float an idea I've been tossing around:
> 
> Over the last few months, I've received several calls from prospective clients who wanted to travel from quite a distance to me for an advanced eyewear fitting. Some have lurked here on optiboard. Some were referred by other optiboarders. I haven't seen any of them. But these situations did point up the opportunity to form some type of qualified-referral network amongst those ECPs who consistently demonstrate adherence to high standards of skill and care.
> 
> Whose ready to help me flesh out this idea, for the benefit of all, including the prospective public who is *not* motivated strictly by price/insurance for their eyewear?
> 
> Help!
> 
> Barry


Barry,

I referred Tom and Barbara; I thought Tom might have been close enough to be practical. I think you referred Matt to me, but I thought he was too far away for it to work out (I probably would have had to send the glasses to him), but I did help him with his Rx and how to find a good optician in his area.

Maybe a "Who's Who" section in the optical forum, with real names and locations? That would be up to Steve of course.

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## kat

I am happy to help anyone in the Phoenix area.

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## roger1

Sure I'd like to go and visit an expert and helpful optician or optometrist but trouble is the glasses are bought and so I guess I need to keep going back to where I bought them and deal with them, unless I want to incur additional cost by going back to my prescribing doctor, or by finding a new optical specialist. I guess next time I'll do my homework first but last time around my experience at the same optical store with my first pair of progressives went fairly smoothly, so I didn't think to try somewhere new. I've had 2 pairs cut so far of the new prescription (Gradal Brevity and GT2) and I'm not feeling very confident that they understand the different types, or the fitting, or my needs very well.

..Roger

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## braheem24

I think I'm gonna open a referral service for all the stupidity I see,

I just had a lady from Wisconsin -2.00ish ou SV with 6BO OD and no prism OS in a drill mount poly. OD dominant.

I told her that after shooting whomever made the glasses for you go see Robert, she's 50 and currently seeing a pediatric OMD 2 hrs away from you but will come see you for the glasses if she does not sell her house and move down sooner.

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## Barry Santini

> I am happy to help anyone in the Phoenix area.


 
Good!  There we go!

I think we may be off to a good start.  Let's try to formalize this.

I think its a whole lot better than getting fitting fees to facilitate online purchasing, don't you think?

B

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## KStraker

Even though you had previous success with the Nikon lenses, I would move to one of the newer digital progressives. Hoya's Lifestyle Id or Shamir Autograph series should be noticeably better. By better I mean less distortion in the periphery, wider channel, and better off axis performance. I know you have already purchased lenses so this may be a moot point.

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## kcount

> Good! There we go!
> 
> I think we may be off to a good start. Let's try to formalize this.
> 
> I think its a whole lot better than getting fitting fees to facilitate online purchasing, don't you think?
> 
> B


I'm happy to help in the Chicago Area and I know my not so close neighbor in Milwaukee would be a great resource.

AS an add on may I recommend that there should be a referral network for speaking. Think back to Dr. Harold Davis in the 70's and 80's. He and 11 other doctors would refer to , invite to speak, and in essence created an environment where they were considered the 'experts'.

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## kcount

> That's going to happen with all PALs at this level of presbyopia, some lenses more than others. It will probably go away with neural adaptation


. 

I Agree.




> That's fine, but at some point you need to hand this off to a professional who can narrow the focus somewhat. Even so, it would take me 45 to 90 minutes of Q & A and trial framing before I would feel confident that I had the right soulution for your specific Rx and visual needs.


. 

First thought I had was, this guy walks in we're pulling down the trial lens set. I'll bet you dimes to donuts we end up backing off the add and resetting the PAL. Roger1 is correct in that it may be a tad high.




> It's not the quality of the lens per se, but the accuracy and optimizing of the lens position, choosing the correct lens or lenses, the Rx, and any modification of the Rx.


Which is why I believ all Opticians should have and use a trial lens set. Their not terribly expensive and make up their costs in one remake avoided. Actually I have used it to actually trouble shoot glasses I didnt make and garnered new patients.






> Thanks for all the replies. Not sure if I'm being criticized or not, here for being an engineer! I think the engineering background just makes me more curious to understand the reasons and not accept "mediocrity" so easily until it's proven to me that's the best I can get. Of course, it might mean I think know more than I do, but I'm aware of that at least.


We're just busting your chops.





> Would my particular prescription be better served with a standard old-fashioned bi-focal (or just a shallow pair of glasses that I look below for near) or would I find the sudden transition from far to near disturbing?
> 
> ..Roger


I have made these in the past. They are simple stop gaps for a patient that isn't ready for a Progressive. The time for this has past in your case.




> Even though you had previous success with the Nikon lenses, I would move to one of the newer digital progressives. Hoya's Lifestyle Id or Shamir Autograph series should be noticeably better. By better I mean less distortion in the periphery, wider channel, and better off axis performance. I know you have already purchased lenses so this may be a moot point.


Not a bad idea but do we want to shake this up that much by introducing a new set of variables?  


Just my thoughts for what its worth.

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## roger1

Ok, can you describe what is different about these lenses compared to a Zeiss GT2? I'm also having trouble finding the difference between the GT2s and the Nikon i's that I have since I guess those are not available in the US, and therefore the "maps" are not on this website. Also the Nikon's are somewhat old now.

Thanks, ..Roger




> Even though you had previous success with the Nikon lenses, I would move to one of the newer digital progressives. Hoya's Lifestyle Id or Shamir Autograph series should be noticeably better. By better I mean less distortion in the periphery, wider channel, and better off axis performance. I know you have already purchased lenses so this may be a moot point.

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## roger1

Can someone explain why the Add power needs to be the same for both eyes? As I said, I think this is too strong for my right eye.

Thanks, ..Roger




> The Add power needs to be the same for both eyes.

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## OCP

> Can someone explain why the Add power needs to be the same for both eyes? As I said, I think this is too strong for my right eye.
> 
> Thanks, ..Roger


I dont HAS to be the same, but if the distance vision is fully and correct balanced, it would be the same in most cases.

Be aware that you cant check that your self, just by closing one of your eyes. Your vision is balanced to binocular vision.

Mike

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## roger1

ah ok, well my simple test is to put on my old distance only glasses that have the same distance prescription as these PALs and then to do a near test (using standard reading test where you look at different size font paragraphs, etc) , and I can tell that the right is somewhat over-corrected with the specified ADD of 2.25. I also am able to remove my glasses and cover each eye and read without any add. So this would suggest that an ADD that gets the distance prescription back to 0 is what I need. I would think that I should go with the minimum possible ADD on each lens, so that the PALs provide the widest corridor and less distortion, since it seems that the corridor width is inversely proportional to the ADD, according to info I've received here.

..Roger

. 


> I dont HAS to be the same, but if the distance vision is fully and correct balanced, it would be the same in most cases.
> 
> Mike

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## KStraker

> . 
> 
> I Agree.
> 
> . 
> 
> First thought I had was, this guy walks in we're pulling down the trial lens set. I'll bet you dimes to donuts we end up backing off the add and resetting the PAL. Roger1 is correct in that it may be a tad high.
> 
> 
> ...


I see your point, I prefer to think of it as optimizing the scenario. I think we can mostly agree that these two lenses live up to the advertising. If he still has the same problems with either of these lenses, it might be time for a flat top. Or, the patient may have to scale down the expectation of equal off axis vision going from a 1.50 to a 2.25 add power. 
     To the OP: yes, the bifocal power needs to be the same on each side. Otherwise, the bifocal area will focus at two different distances. Think of the distance correction as getting you back to a zero point. The add is on top of that zero point.

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## Fezz

Ugh!

Enough is enough already!

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## Steve Machol

As per the OptiBoard Posting Guidelines:




> This forum is for Eyecare Professionals. Consumers are allowed to post in the Just Conversation forum and non-optical topics only. Please be aware that any questions involving optics or eyecare may be removed. These kinds of questions should be discussed with a qualified eyecare professional who has examined you and is familiar with your situation.

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