Dual ADD

[vikramg]

I believe the Dual ADDs progressives have a progressive surface on Both sides of the lens , Something like Definity from J&J having a fixed 0.75 addition progressive on one side and your Freeform RX progressive on the other .

Can anyone confirm whether this idea of spreading the addition on both the surface of lens, leads to any gross or visible benifits in the various zones OR

Do the rules of optics and physics still limit the zones and this is just another way of charging more from the customers ?

[slaboff]

My understanding is that it increases the zones by bringing the add closer to the eye.


shamir has patented the backside only version... so all others are a mix of backside and frontside add powers.

[CDOT]

shamir has patented the backside only version... so all others are a mix of backside and frontside add powers.[/QUOTE]

The rodenstock multigressiv ILT is backside only

[HarryChiling]

I understand the benifits of the back side add, however; I don't think I understand the benifits of splitting the add. The definity lens does not seem like that great of a lens they just mixed the old technology with the new. If anyone has any clarification on the benefits please post.

[AWTECH]

FYI: Shamir does not have a patent on back side progressives.

[Bobie]

Dual ADD must be good , because even Ess.... who almost anti-Free Form Technology for more than 5 years ( because , it was low profit ) , but now Ess... have to buy Dual ADD Technology from JJ and lunch Vari... Phys.. 36. , that almost copy concept of JJ Defin..2 and Hoyalux iD.

Sorry that , we can not write the full name of Ess... product , because in Thailand , this name is untouchable.

The most advance of Dual ADD is to reduce distortion around the near zone that increase by ADD to fixed the problem of Vari... Pana... and Vari... Ips.. that put the astigmatism error around the lenses and have poor quality of vision at night , these why they have to hurry up to buy technology from another PALs company and lunch Vari... Phy... 360 and try to say , oh now , we have very good quality of vision PALs.

[Robert Martellaro]

I believe the Dual ADDs progressives have a progressive surface on Both sides of the lens , Something like Definity from J&J having a fixed 0.75 addition progressive on one side and your Freeform RX progressive on the other .

Can anyone confirm whether this idea of spreading the addition on both the surface of lens, leads to any gross or visible benifits in the various zones OR

Do the rules of optics and physics still limit the zones and this is just another way of charging more from the customers ?

The conventional wisdom is that what can be done on two surfaces can be done on one surface. However, by placing the add on the back of the lens (I believe Seiko holds the patent rights), the near zone will be about 1mm closer to the eye, increasing the near field of vision a very small amount. Furthermore, most of the back surface add designs use very complex curves that decrease oblique astigmatism and power errors- increasing the area of clearest vision, especially with Rxs that have >1.75 cyl.

Regards,

[Bobie]

I would like to hear any comment from the wearer who ever try out JJ Defini..2 , Hoyalux iD and Vari... Physi. , because I don't think they are difference in real used , but they are just difference only JJ Defini..2 lunch first , Hoyalux iD lunch second and Vari... Physi. lunch later.

[vikramg]

Bobie ..

Instead of looking at the marketing literatures handed out by most companies each claiming their progressives to be better than the others , I suggest you look up Dr Sheedys work available at the below link .

http://www.optometry.osu.edu/research/coor/4059.cfm

Read the paper Progressive addition lenses-matching the specific lens to patient needs. where he compares definity with others .

In his research you can see that the Definity only tops in Intermediate width and is about average in all other aspects .

I am not convinced that this dual progressive surface will offer any real benefit to the consumers .

[Bobie]

Dear vikramg ,

Thank you for your URL of the paper Progressive addition lenses-matching the specific lens to patient needs , that Essi... never agree ( because , they only agree with the paper that say their PALs is the best or if no third party said , then they will set up their third party like clinical study that control every parameter and Rx in their way and try to make the world believe that , their PALs better than AO Compact , Rodenstock Impression ILT.

The funny clinical study that they have been set up was to make us believe that , their expensive Semi-Finished Progressive Front Surface PALs is much better than The Individual Free Form Technology like Rodenstock Impression ILT.

The paper of Dr Sheedys that compares Defini.. with others that show us the Definity tops in Intermediate width is very important point , because we can seperate good PALs , bad PALs , best PALs in Intermediate width , and any PALs that have good Intermediate , always better than other PALs in real used , these are the answer why the untouchable PALs company worry about J. Defini.. and have to take over J. Defini..

After they take over J. Defini.. , they can lunch new PALs in the exactly the same concept of J. Defini.. , but they said , oh , our 500 genius design the new PALs and bla.. bla.. bla.. bla... . After I have been read what they claim , I have been laugh and think oh , may be they think , the optik shop and the consumer around the world are stupid and I would like to see the U.S. PATENTED of their PALs.

The most about the same of J. Defini.. , Hoyalux iD and Va.... Phy.. 36. are at below ;

• Ground View Advan.... vs Balance View Control vs Near Power Con....
• Dual Addition
• 30% wider Intermediate Zone

The most advance of Double Side Progressive Surface is the wider intermediate zone and reduce the distortion around the near zone and below 100% of Addition in big frame that Hoya call " Balance View Control "

In Thailand , some PALs company try to lied us that their " Very Expensive Semi-Finished Progressive Front Surface PALs " is better than " Free Form Technology PALs " like Hoyalux iD , Rodenstock Impression ILT , may be they also think , the Optometrist & the Opthomologist in Thailand are stupid too , but I would like to inform them that , we are not stupid.
:cheers:

[vikramg]

Some PAL may be they also think , the Optometrist & the Opthomologist in Thailand are stupid too , but I would like to inform them that , we are not stupid

Bobie Most PAL companies like to believe that the opticians are stupid ....

That is why they never bother to provide Spherical and cylinder plots of their progressives ???

They feel that the optician should just buy their empty marketing talk and internal research !!!

I feel voices like Dr Sheedys are voices of truth which bring some element of objectivity among these mad marketing claims.

Dr sheedys research also throws up another interesting fact , that a lot of the progressives leading his rankings like Genesis and Image were designed atleast 10 years ago , so we are hitting a wall as far as real, (demonstrable)improvements in progressives are concerned ..

[chip anderson]

If we start referring to these progressives as "dual add" how we gonna keep from getting confused over the true dual adds such as the double D's?


Chip

[MTP]

We use the Seiko inner surface progressives and generally find them to be very good, except for hyperopes > +3.00, where they advise adding +0.25 to the add to counter the loss of spectacle magnification. I wonder if the thinking of having +0.75 on the front is to give some additional spec. mag, without introducing distortion beyond that from the back surface add.

[Darryl Meister]

The rodenstock multigressiv ILT is backside only

The SOLAOne HD is also a back-surface design.

[Chris Ryser]

Bobie Most PAL companies like to believe that the opticians are stupid .... ....................
................................... so we are hitting a wall as far as real, (demonstrable)improvements in progressives are concerned ..

Very interesting, but maybe true

[crystaloptical]

Hi, I read you discussion about PAL Lenses. Perhaps one of you can help me. I repair mostly instruments and don't do much with lenses. One of my customers asked me to get her a price on a PAL ID. I don't know what that is. Is it the light full of dots they hold a lens over so they can see changes in the prescription?

Can you sugest a low cost source for one? Anybody have a used one they want to sell?

Thanks, Joel

[Bobie]

Hi,crystaloptical

Please click to http://www.pal-id.com