Why has the worst optical surface ever become the biggest money maker ?

[Dr. Bill Stacy]

I wouldn't buy a camera with 30 to 40 percent distortion.

Well the best cameras in the world often blur more than 50% of the photo for a reason. Like the young human eye, if it focuses on an object say 12 inches away, that object will be crystal clear, but all more distant objects will be blurry, unless things are very bright and the f stop is minimized. I like the subject to be clear and the background to be blurred. Often seems more artistic.

[fjpod]

We all know that our focusing flexibility gets limited as we get older.

Is it really the worst optical surface ever invented if it allows one to see clearly at all distances (assuming you look through the right zone).

I think it is remarkable.

[Dr. Bill Stacy]

We all know that our focusing flexibility gets limited as we get older.

Is it really the worst optical surface ever invented if it allows one to see clearly at all distances (assuming you look through the right zone).

I think it is remarkable.

One man's junk is another man's treasure...

[Lelarep]

I know more than a few patients that were PAL non-adapts who also hated lined bifocals. The switched to a system I've seen trending recently, carrying a pair of readers they can put on over distance lenses

[Jubilee]

I do use a Chemistrie clip for extra plus on my crafts. Sometimes with beading, chainmaille, and other near intense crafts, I like to increase the plus through the whole lens.

[Happylady]

I have never had a problem adapting to a PAL and have several of them nicely stored in their cases.

I don't think this is so, you have never liked wearing progressives. I do believe you when you say you have several stored in their cases, though!

I will agree it's best to start with progressives in the 40's but I know plenty of people who have started in their 50's and even later and been fine. I've also had patients dislike lined bifocals. I've never worn a line, but I've tried them on and I see the line. I guess after a while you don't notice it.

I work with a number of people who also happily wear progressives but we have one man who didn't like them.

As as for being the biggest promoter of progressives- I don't think this is true. Many people here have disagreed openly with you about them.

[Chris Ryser]

I don't think this is so, you have never liked wearing progressives. I do believe you when you say you have several stored in their cases, though!


As as for being the biggest promoter of progressives- I don't think this is true. Many people here have disagreed openly with you about them.

My work is done mostly on my desk in the company, at home and in my winter house in Florida. In each of the three locations I have a desk that fits into a corner, with all the useful gadgets at my fingertips by just swivelling the chair to the right or left, and sometimes moving it a foot or two.

I use only large screens for my computers in all locations, and have some certain programs as OptiBoard enlarged to 30 cm or 12 inches, and would not even need glasses to read and post.

However I love my glasses I call my own design for that purpose. They are not the most fashionable looking but by far the best working I have been able to come up for my own use.

I made a pair of ST 35's in an aviation shape 54 mm on the horizontal with the bifocal line at the lower edge of the pupil.'

A new deep square plastic frame I still have instock for 25 years was reformed and stretched to fit the aviation shaped lenses.

I can now see my telephone to the left totally clear and my printer/scanners to the right by just turning my head about 15 degrees through the edge of my glasses.

This is no rocket science but a superb practical working solution.

I had to compare this with one of my PALS in the desk drawer, and it is very clear that the progressive are the losers in this contest.

[AngeHamm]

Your personal experience, no matter how experienced or well-informed, does not negate the experience of millions upon millions of very happy PAL wearers. I don't understand your insistence on taking optics back to the 1970s. Let knowledgeable optical professionals sell what they think is best and you can sell what you think is best.

[Uilleann]

So - looking so far off axis in a FT design, the marginal astigmatism, prismatic problems, and chromatic aberration would make many people sick. Just as you claim that PALS are un-wearable for you, they are a perfectly viable and comfortable design for the majority of presbyopic spectacle wearers today.

To state they are so bad as to merit completely ignoring them and mandating a return to 1770's lens technology is myopic in the extreme.

[kaledarkwind]

I mounted a 6x magnifying lens on my workbench for doing MicroMaille....

[Golfnorth]

Based on Chris' details, facts and figures I will stop selling progressive lenses immediately!
If someone wants progressives I will refer them to the store down the street.
I will NOT sell my clients inferior products, it's Flat-top 35's for me from now on.

Regards,
Golfnorth

[MakeOptics]

Well the best cameras in the world often blur more than 50% of the photo for a reason. Like the young human eye, if it focuses on an object say 12 inches away, that object will be crystal clear, but all more distant objects will be blurry, unless things are very bright and the f stop is minimized. I like the subject to be clear and the background to be blurred. Often seems more artistic.

That's not because the lens is inferior but the lens system can only be designed for one object distance often times infinity when using the standard lens. Opening up the aperture means more paraxial rays which are prone to defocus but you are right it collapses the depth of focus for a more artistic shot and highlights the subject. A new type of camera does exist called a lytro which not only capture quanta but direction of light so even afterwards the depth of focus can be adjusted. It's neat technology but wouldn't work for eyeglasses without replacing a direct image for an LCD viewfinder.

[MakeOptics]

My work is done mostly on my desk in the company, at home and in my winter house in Florida. In each of the three locations I have a desk that fits into a corner, with all the useful gadgets at my fingertips by just swivelling the chair to the right or left, and sometimes moving it a foot or two.

I use only large screens for my computers in all locations, and have some certain programs as OptiBoard enlarged to 30 cm or 12 inches, and would not even need glasses to read and post.

However I love my glasses I call my own design for that purpose. They are not the most fashionable looking but by far the best working I have been able to come up for my own use.

I made a pair of ST 35's in an aviation shape 54 mm on the horizontal with the bifocal line at the lower edge of the pupil.'

A new deep square plastic frame I still have instock for 25 years was reformed and stretched to fit the aviation shaped lenses.

I can now see my telephone to the left totally clear and my printer/scanners to the right by just turning my head about 15 degrees through the edge of my glasses.

This is no rocket science but a superb practical working solution.

I had to compare this with one of my PALS in the desk drawer, and it is very clear that the progressive are the losers in this contest.

The real test I have found is not only clarity but in my case would my wife claim me as her own out in public wearing a pair like that. Consumers have spoken loudly and proudly cosmetic ignored is unacceptable in the majority of circumstances. Good for you that function takes such high precedence over form, but surely you are not suggesting that another opinion isn't allowed.

[Dr. Bill Stacy]

That's not because the lens is inferior but the lens system can only be designed for one object distance often times infinity when using the standard lens. Opening up the aperture means more paraxial rays which are prone to defocus but you are right it collapses the depth of focus for a more artistic shot and highlights the subject. A new type of camera does exist called a lytro which not only capture quanta but direction of light so even afterwards the depth of focus can be adjusted. It's neat technology but wouldn't work for eyeglasses without replacing a direct image for an LCD viewfinder.

Of course. I was just pointing out that fine optics even cause distortions in some parts of the image, usually on purpose. And to compare camera optics with eyeglass optics is generally not a valid comparison. In the extreme, some "fish-eye" lenses distort the image over 100% of the view.

[MakeOptics]

You being an optical wizard, what would you do with a PAL, you are still too young for that. And if you would wear any, your ad be in +0.50 Dioptres.

The question I asked was presenting the real facts and nothing else, and if you don't like it, please just ignore the whole thread. It is only one day old.

A few years back I got tired of hearing that as an excuse to remove me from PAL discussions so I ordered a pal in my prescription with a +2.50 add, effectively removing that excuse from table. I did have issues adjusting but after a week they were acceptable, the only caveat was I had a choice and often found myself taking them off for extended up close tasks, however that lead me to emphasizing the importance of secondary and tertiary pairs. I started discussing NVF sooner with presbyopes and informing them that at a certain point we are going to address the additional needs.

[MakeOptics]

Of course. I was just pointing out that fine optics even cause distortions in some parts of the image, usually on purpose. And to compare camera optics with eyeglass optics is generally not a valid comparison. In the extreme, some "fish-eye" lenses distort the image over 100% of the view.

Spot on yes they do, I think the big takeaway is we are all still searching for the perfect pair.

[Plausible]

[QUOTE=Chris Ryser;516525]

However I love my glasses I call my own design for that purpose. They are not the most fashionable looking but by far the best working I have been able to come up for my own use.

I made a pair of ST 35's in an aviation shape 54 mm on the horizontal with the bifocal line at the lower edge of the pupil.'

A new deep square plastic frame I still have instock for 25 years was reformed and stretched to fit the aviation shaped lenses.
QUOTE]



Pictures on both please or they didn't really happen.

[Happylady]

Yesterday at work I had an older woman comment that she disliked her bifocal glasses she bought somewhere else. She was a previous progressive wearer but wanted to save some money and went with bifocals. She doesn't like them, the line bothers her.

Not a a new story, I've heard the same thing many times. And of course I thought of this thread while she was talking!

[Chris Ryser]

To state they are so bad as to merit completely ignoring them and mandating a return to 1770's lens technology is myopic in the extreme.

Just went on Google now in 2015 and asked the question:

"optically pure surface versus distortion on it"

and the answer was:

About 23,400,000 results (0.48 seconds)

This is no science, you can start learning again before sending somebody back to the 1770s

[Uilleann]

Sorry. This entire thread is nothing but trolling.

Most of us here are both aware and tired of it. Please give it a rest.

[Dr. Bill Stacy]

Just went on Google now in 2015 and asked the question:

"optically pure surface versus distortion on it"

and the answer was:

About 23,400,000 results (0.48 seconds)

This is no science, you can start learning again before sending somebody back to the 1770s

Actually, if you put that phrase into google with the quotes included, you get just 2, well maybe 3 as soon as the googlebot finds this one. you obviously omitted the quotes and got 24 million returns of which 23,999,997 have nothing to do with this discussion.

[Chris Ryser]

Sorry. This entire thread is nothing but tolling.

Most of us here are both aware and tired of it. Please give it a rest.

I can just say that there is no tolling here, I just had no access to the computer for a few days.

As I am now back in normal action I will continue my thing as I please and do not believe that you are talking about most of us.

Just ignor this thread.

[Uilleann]

Chris - when you post misleading claims on a public forum, you can and should expect the public to refuse your claims. Your "data" has been proven outright false, and apart from your overt attempts to continually sell your products on the board, or reminding everyone how you invented everything related to the optical field in the past 40 years, this sort of trolling appears to be the only thing you're bringing to the table.

Seriously, it's old. Give it a rest.

[Chris Ryser]

Your "data" has been proven outright false,

Just prove right here on OptiBoard that a progressive lens of any make has a perfect optical curvature outside the progressive part, and no distortions whatsoever, and I will officially apologize.

[fjpod]

Just prove right here on OptiBoard that a progressive lens of any make has a perfect optical curvature outside the progressive part, and no distortions whatsoever, and I will officially apologize.

Chris,

One might say that progressive lenses do have "perfect" curves...for the purpose intended...that is, seeing clearly at all distances with a seamless transition(at least when looking through the channel). Sure, we all wish the channels were wider, but we know that optically speaking that is not possible. A lined bifocal can't do that. Even a trifocal can't quite give you the smooth transitions from distance to intermediate to near...and with a trifocal, just a little head movement out of position and the wrong seg is in place at the wrong time. So, when you get into advanced Multifocal optics, nothing is "perfect". Even though the peripheries are not perfect in a VFL, the channels can do something that no other lens form can.

In my experience, most patients who have trouble adapting to VFLs, and who perceive the lenses as imperfect, are those who don't understand or don't need the quick transition at all distances. Another group consists of prescribers who over-correct patients who have near normal vision at most distances.

So, while we can find a lot of areas on a VFL that are unusable....there is one area that works better than anything else. So, in my mind, it is "perfect".

You realize this is a philosophical discussion....