Progressive Lens Design: Where do we go from here?

[Pete Hanlin]

New equipment is on the horizon which will customize RX based on PD, seg height, vertex, as well as RX. Semi-finished lenses will become "hockey pucks", much like Gas Perm Buttons.
I'm convinced this statement pretty much sums it up. People love to personalize products to themselves (one survey showed 37% of people were willing to pay 20% more for a product that was customized to their particular needs).

In the future, I think the patient will be able to specify the softness, progression curve, and position of the channel by answering a computerized survey of their particular visual needs.

What PAL lens is the current 'State of the Art' and why do you think so? In particular, what optical advantages does it have over older designs?
I'll say the Panamic is current state of the art, even though I believe there are some Hoya and Rodenstock products out there that are more advanced. I'll use the Panamic as an example, however, because it is widely used and has a number of features that represent the new generation of PAL (e.g., multi-design based on both base curve and add power, positional symmetry between the eyes which produces better binocular vision, etc.). I'm not positive if the Panamic uses "as-worn" optimization, but that's another advancement that deserves note (I know Pentax's lens is designed with fitting characteristics in mind).

To sum, I think we've gone about as far as we're going to with current materials and "stock" SF lens blanks (although this weekend our Hoya rep was touting some "sensational" new PAL that is supposedly "far beyond" the Panamic... we'll see). Further development will probably come as suggested earlier- through customization to the patient.

[Ron]

Steve, if you minimize the distortion on the cylinder side, the lens will be very easy to adapt to and be thinner. Also if the lens is molded, there are no surfacing marks that reduce light that goes thru the lens. There are several more reasons but those are 2 real good ones.

[Steve Machol]

Ron said:
Steve, if you minimize the distortion on the cylinder side, the lens will be very easy to adapt to and be thinner.

Honestly I don't follow this at all. Can you elaborate? What are the optical principles involved? Of course whenever you can minimize distortion, optics improve - that's a given. But one of the main features of PAL lenses is that when you minimize distortion in one area it has to go somewhere else. You can compress the distortion into smaller areas, but then you move closer to the older 'hard' designs like AO UltraVue and Younger 10/30. You can also spread the distortion out which then brings you closer to the more recent 'softer' designs. (At this point it would be interesting to get Darryl Meister's input on this issue.)

Also if the lens is molded, there are no surfacing marks that reduce light that goes thru the lens.

Sounds good in principle, but again what are the practical benefits? Assuming that we are talking about a properly surfaced lens, are 'surfacing' marks measurable and in any way noticed by the human eye? What clinical studies support this conclusion? Also most surfaced lenses are backside coated. What effect does this fact have on this claim?

Don't get me wrong, I'm not picking on you. But it seems to me that there are very few actual clinical studies and wearer trials being done today to support the myriad of claims being made about the optical benefits of one product over another. Food for thought! ;)

[Pete Hanlin]

It looks like you guys are in the same Arizona town, so you should discuss PALs over a cinnamon bun and coffee some time!

All the hype aside, Steve has a point. Facts are, in a PAL you have to get from point A (the distance Rx) to point B (the near) without the aid of a segmented line. Getting rid of that line causes distortion. You can cram all the distortion into the tiniest space possible (basically a blended lens), or you can spread it out evenly as possible all over the lens- but it will always be with us.

I suppose you are speaking of atoric or aspheric ocular (back surfaces), which is already being done by a number of manufactuers (e.g., Rodenstock's Multigressive). Are the newer designs more comfortable to wear? According to the patients who I've switched from VIPs to Panamics, the new design works much better. Does each and every new design we see really usher in a grand new concept in vision? Of course not.

My theory is that the key to success with any PAL (new or old) comes down to the expertise of the fit. I like to think of the corridor as a keyhole. Center that key hole as close to the eye as possible, and you'll have good vision. Slap it haphazardly in front of the eye and you'll get the whole gambit from "works fine" to "can't see a thing!" Sure, use the best designs out there (Panamic, SolaMax, LifeC, etc.), but realize that PALs are like golf balls- some have the potential to go farther and straighter than others, but you still have to hit the dang thing just right to make it work!

[Joann Raytar]

According to the Enigma website, they are planning on rolling out a PAL they just don't have an available date.

[sandeepgoodbole]

Steve Machol said:
I think the suggestions on fitting techniques for PALs is one area of potential improvement. However in spite of 15 votes stating that 'much more could be done' with PAL designs I still haven't seen a single response that indicates what exactly that is. Perhaps I worded the question poorly.

Let me ask it another way:

What PAL lens is the current 'State of the Art' and why do you think so? In particular, what optical advantages does it have over older designs?

Just ignorant about this thread, 10 minutes earlier I have asked
a Q about pals. That Q itself has a suggestion which I think could be the Potential Improvement :
Instead of "Corridors" : "Rows "of progression would be making them much better. :cheers:

[yzf-r1]

:idea:

if a PAL was intended to be a 65mm uncut, would it not be possible to design it as though it was going to be say a 80mm uncut, then the distortion would be not only be far out in the periphery, in fact it would all be edged off, and you would end up with THE perfect progressive lens.

I know, i know, it sounds so daft, furthermore if it was possible someone would have already thought of it. All you lab rats and lens experts will post and tell me that it is not possible, but what i want to know is why not???

yahya

[myodisk]

Sola came out (very boldly) with the "Smart Seg" (Stupid idea) It has all the worst traits of both standard multi-focal and progressive addition "invisible" bifocals..... put a progersssive lens in a flat top design????

This may sound stupid, but can some explain to me why no one has come up with a "blended executive trifocal"??? Is this not we we all want the perfect progressive to be?

1. unlimited width at all distances with no perephrial distortion
2. easy adaption with no "swim"
3. cosmetic acceptance with no "lines" or image jump.


I guess I just dont get the physics, otherwise I'd be a rich man..

[sandeepgoodbole]

[This may sound stupid, but can some explain to me why no one has come up with a "blended executive trifocal"??? Is this not we we all want the perfect progressive to be?

1. unlimited width at all distances with no perephrial distortion
2. easy adaption with no "swim"
3. cosmetic acceptance with no "lines" or image jump.

That's Excatly what I wanted to say.. you have refined what I am calling Exceutive Pals last couple of days ..That would be great!:cheers:

[Steve Machol]

I hate to burst everyone's bubble but there is no way to create a progessive surface without some distortion. If you think this is easy to do, then try it yourself with some model clay. Cover the surface of a Flat-Top or Exceutive bi/trifocal lens with clay. Then carefully remove the clay retaining as much of the original surface topography as you can. Now use your fingers to smooth out the lines without reducing the reading area or introducing other distortions.

If you can do this, then immediately locate a patent attorney. You are destined to be very rich indeed! ;)

[shanbaum]

Steve Machol said:
If you can do this, then immediately locate a patent attorney.

Or an exorcist.

[Refractingoptician.com]

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[Refractingoptician.com]

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[John R]

Gary said:
Randomly aimed it at whatever. The result ? A beautifully focused , full field picture of whatever it was aimed at.

Now that is a real progressive lens !!

Mmm, but a bit bulky to have in a pair of glasses....:hammer:
You can have this now...You just need a pair of s/v specs for every distance..

[Refractingoptician.com]

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[paw]

I think lens designers? manufacturers? marketers? need to consider that state of the art can't get TOO expensive for the average Joe Eyeglasses. We are told by marketing materials to encourage second pairs and prescription sunglasses. How many people are going to spend this kind of money before they figure out that one zap of LASIK is more cost efficient in the long run?

[John R]

paw said:
I think lens designers? manufacturers? marketers? need to consider that state of the art can't get TOO expensive for the average Joe Eyeglasses. We are told by marketing materials to encourage second pairs and prescription sunglasses. How many people are going to spend this kind of money before they figure out that one zap of LASIK is more cost efficient in the long run?

I think LASIK has a long way both in terms of time and cost before it becomes more cost effective. Dont forget even after LASIK folks will still need glasses. Sure not as bad powers but glasses all the same. Untill someone comes up with replacement lenses that can replace your damaged ones in your eyes then glasses are here to stay.

[John R]

Gary said:
Actually, the camera's auto focusing mechanism has already been adapted to help low visual acuity people get back into the school classroom. The idea is not far fetched.

Eye position sensors are a reality . Auto focusing sensors are a reality. Adjustable , controllable lens systems are a reality. The two together with computer chip technology may well be tomorrows answer to full field sight .

Yes these things may be around now, but like many other so called inovations that make the headlines. How long if ever will they find their way to the general public's market place.
Sure stuff like auto focusing on camera's works but look how bulky it is even on the smallest camera's compared to a pair of frames which it will have to be fitted into...Moden frames are getting smaller in all ways, which leaves less room for this type of technology.

[Di822]

Well, all I can tell you is from my own personal experience. Fifteen years ago, I went into my first progressive. It was something from Pearle. Seems like it was a Sola XL. Not sure.
In 1991, I began selling the Comfort by Varilux. For the first time, I could read easily without having to work at it. The periphery was "ok". I could tolerate it. Then I went to the Panamic when it came out a few years ago. The periphery was much better. Not a lot of change otherwise. This year I am promoting the Hoya Wide and Hoya Summit. This was the most remarkable change I have ever experienced. The optics in the Phoenix Hoya are awesome. It has the clarity of looking through glass to me. I haven't seen things so sharp in 15 years. I presume it is because of the higher ABBE value. I have not had one non-adapt in 6 mos. of selling it. And I have switched all my Varilux people to it without a single complaint. Matter of fact, I see them experiencing what I saw the moment I put their glasses on them. It is almost like having AR on your lenses. Very clear.
Does anyone have experience with this lens and know more about it than me?
I AM THE " X VARILUX QUEEN"

[Optical Plumber]

paw said:
How many people are going to spend this kind of money before they figure out that one zap of LASIK is more cost efficient in the long run? ...

There will always be a significant percentage of the population who for one reason or another (dangers both real and imagined) will never permit the wielding of sharp objects in the vicinity of their eyeballs.

Terry

[Optical Plumber]

Adaptive optics could potentially provide an incremental improvement over the best of today's PAL designs. This technology has already been hinted at by several of the posts in this thread. Here is an excerpt from Adaptive Optics Discussion

Some of the technology derived from adaptive optics (AO) research is already being used by ophthalmologists to measure aberrations in the eye with unprecedented accuracy, and it may not be long before AO-based devices replace the conventional phoropter used to calculate prescriptions for eyeglasses and contact lenses. In addition, researchers are using adaptive optics technology to obtain extraordinary views of microscopic structures in the eyes of human subjects

Taking this idea one step further, one could use the data from the Adaptive Optics phoropter to generate a customized surface on the lens. This technology, however amazing it may seem, will STILL suffer from the frequently mentioned flaw of peripheral distortion in PAL designs.

It seems to me that the idea of a true variable focus lens such as is found in cameras, combined with adaptive optics technology will be the ultimate future of NON-intrusive vision correction. In my wildest imagination, I see a flexible lens, with the shape controlled in much the same way as the human eye's lens is controlled.

On the otherhand CCD and nano-chip technology should eventually provide the ability for everyone who is willing to undergo the necessary cerebral implant, to see everything (infrared, ultraviolet, night vision, etc.) with 20/10 vision.

After this, Xray vision should be a cake-walk!

Terry
:D

[ogEE]

a new pal design is available in germany from ZEISS. this lens is "built" on an individual basis using 9 perameters. to do this you need a $30K piece of equiptment called a video infral system. this lens will not be available to the USA market untill about 2004. check it out at www.zeiss.de. i think you will see lenses in the future that will move beyond the constrictions of physics. how about an LCD lens that changes foci as the cysiline lens changes it's shape??? the computer is a box; the MIND is infinate. thats my perspective. and yours?
yours in optical fun,
ogEE (aka phil harris )

[dfisher]

Custom progressives are the upcoming "next generation" of lenses. Some are "custom molded", a technology I don't at all understand, but two German companies are doing true custom front surface design based on PD, vertex, Rx, add, frame dimensions and who knows what else.

How about:
* The optimum base curve for *every* Rx?
* Corridor length based on the "B" measurement
* Change the with of either the intermediate or near
( based on occupation or lifestyle.)

These are just a few of the things that can be customized for each Rx. And as R&D continues, the software can be refined to create the next "next generation" lens.

Zeiss Individual is coming very soon. And in Europe, the Rodenstock Individuality and Impression ILT are available using this very technology. From now on new designs will simply be software updates.

[Nikki B]

see www.discoverylens.com for details :D

[dave lien]

Steve,

Would there not be some optical beneifit if the design on a progressive could be atoric? With a more indepth rx range then what is now in single vision My thinking here is that there would be less distoration. Thus an improvement on lens design.

Dave