Why are some progressive lenses still so horrible?

[edKENdance]

Had a client who purchased new progs at a trendy new place in British Columbia called Bailey Nelson. If you haven't heard of them you should google them up. They mailed them out to her when they were ready since she lives here which is halfway across the country. Her rx was a +1od +2os distance with a 225 add. The progs were private label so I couldn't tell what design they were using. The segs were bang on (assuming a 4 drop. Classic P3 fit at 23). The powers and pd were perfect but her vision through them was bad. Peripheral blur. No discernible intermediate and a reading area she called "pin size". She ended up picking a new frame from us that was the same shape and I fit her at virtually the same height. I used a Nikon Digilife. I was a little nervous when she came to pick them up today. The ones she got from BN were her first progressive and maybe her expectations of how progressives worked were a little high. When she put the new ones on the difference was night and day. Everything was perfect and manageable. After she left I breathed a huge sigh of relief but I can't stop thinking about why those other progressives were so bad. Their website says they use the same labs that supply lenses to offices across Canada. I can't remember someone having such a bad experience with a prog when all the measurements, powers etc... were so good. I'm scratching my head here.

[idispense]

If you have her lenses then run them through a topographic mapper, like a Rotlex mapper. That may provide the answer in a visual format.

[edKENdance]

If you have her lenses then run them through a topographic mapper, like a Rotlex mapper. That may provide the answer in a visual format.

Of course! I think I might have one sitting in one of the trunks of my vintage Porsche collection but that would require me to fly to my car storage facility in Dubai and I don't have the time to do that presently. The frames and lenses are also en route to the BC location for a full refund.

[idispense]

Some independent labs have them.

[Robert Martellaro]

Her rx was a +1od +2os distance with a 225 add. The progs were private label so I couldn't tell what design they were using. The segs were bang on (assuming a 4 drop. Classic P3 fit at 23). The powers and pd were perfect but her vision through them was bad. Peripheral blur. No discernible intermediate and a reading area she called "pin size".

That perfectly describes a progressive addition lens, except that the distance peripheral vision can vary substantially between designs- some with a generous distance zone width, other designs blur quickly and noticeably off-axis.

Her initial assessment is par for the course, especially for a first-time PAL wearer with an add that's more typical for a fourth generation presbyopia correction, not a first-time wearer.

Her quick adaptation to the new lenses was partly due to a more appropriate PAL design, maybe in a more optimal position, and from prior neural adaptation. Congratulations- you have another new lifelong client.

[edKENdance]

That perfectly describes a progressive addition lens, except that the distance peripheral vision can vary substantially between designs- some with a generous distance zone width, other designs blur quickly and noticeably off-axis.

Her initial assessment is par for the course, especially for a first-time PAL wearer with an add that's more typical for a fourth generation presbyopia correction, not a first-time wearer.

Her quick adaptation to the new lenses was partly due to a more appropriate PAL design, maybe in a more optimal position, and from prior neural adaptation. Congratulations- you have another new lifelong client.

Thanks Robert. I was always under the impression that a design would excel in respects that it failed in others. Small distance in exchange for wider near as an example. This seemed to fail all over. Prior Neural Adaption is a wonderful sequence of words that I am going to start using on a daily basis. :)

[Tallboy]

Also with Full backside free form, The progressive optics can just be completely off because of faulty processing - WEIRD things can happen. It is why you must trust your surfacing lab more than ever before. When I used to surface ovations and illuminas I never had to worry about things like that

[DanLiv]

And as we know even from our own labs progressive lens prices can vary as much as 2000% from the cheapest to the top of the line. Though I personally have had success with even my labs' lowest price progressives, I'm sure there are some abysmal 30+ year old designs still being produced. Even if the lens is "new", if it's based on an outdated design even digital surfacing can't save it from underperforming even basic modern designs.

[idispense]

And as we know even from our own labs progressive lens prices can vary as much as 2000% from the cheapest to the top of the line. Though I personally have had success with even my labs' lowest price progressives, I'm sure there are some abysmal 30+ year old designs still being produced. Even if the lens is "new", if it's based on an outdated design even digital surfacing can't save it from underperforming even basic modern designs.

nice web site and discussion of pd measurements Daniel