Shamir office PALs

[drk]

Does anyone know how these things are designed?

Do they:

a. have a "targeted add power" for the lens designs (called "Computer" and "Workspace")

b. have a "percent of add in the computer distance" area?

c. have a degression?

[Uilleann]

a. Magic.

(to elaborate, the "Computer" is designed for people with almost all screen and desk work exclusively, with a *slightly* wider corridor. The "Workspace" design gives greater distance viewing up to roughly 8-10 feet out, such as a boardroom table setting, with the tradeoff that the corridor is slightly narrower.)

b. Varies slightly based on add power, and lens design chosen (see above).

c. Yes, varies based on full add power and Rx however. I don't know the alchemy their algorythm uses, but I'm told it involves quicksilver, unicorn farts, and various humours.

[lensmanmd]

Not sure about Shamir, but IOT is roughly 40/60 vs 50/50, regardless of degression and "viewing" distance. Most screens are no longer placed 36" away, rather 48-50", so the 40% works its unicorn fart, rainbow dust magic. I'm sure that all degressive office designs work off similar algorithms. Zeiss or IOT, they seem the same to me.
I wear all modalities, and tend to prefer the 2m variation for daily office work, though the 4m is good for when you need to get up and walk around without switching glasses. Yes, it is a thing for us older ones. The 1.3m version is a bit confining, I find, but great for laptops on a plane, in a no legroom, no personal space, cattle call class type of flight.

[drk]

I now feel dumber than before.

[Uilleann]

Doc - trust the unicorn.

[drk]

I'm not ready to sample the rainbow sherbet unicorn poop just yet...

Ok, say it's plano with a +1.50 add, and you are going with the "Shamir Computer" which is a fairly straightforward design need, and I'm "Bob Shamir" designing my lens.

I could do this:
a. "I think all computers tend to sit in the 66 cm range, so I'll just mandate...a +1.00 add for everyone. The leftover will be in the bottom of the lens."
b. "Everyone needs a computer lens, even those with low adds, but we must make the computer add proportional to the near add....so I'll put about half the add in the distance...+0.75..."
c. "I think I'll just take the add power and back it down by a set value...let's say...-1.25D...so the computer add will be +0.50."

[drk]

Where this comes up is where the patient DOESN'T like the intended design after dispensing, and you have to fix the problem. You can't just order "a little lighter on the mayo" you have to start with a new "prescription" (since these are ordered straight off the spectacle Rx and like the bro's said...magic is performed).

So the "new prescription" has to be fudged by whatever you end up "over-refracting" with flippers and the patient sitting at your office computer with a big, fat frown. That's kind of a sloppy method, no?

Wouldn't it be nice if you could just say "degress more" or "use the 30% add formula instead of the 50% add formula" or whatnot?

[juno]

I know in one of John's OpticianWorks videos on office lenses, he recommended waiting until a patient was at about a +2.00 add before giving the office lenses a harder look. Before that and I think he said based on his experience the patient just didn't really notice it? Can't find the vid at the moment to verify

[drk]

It's a valid point.

If you're talking about (constant) blur, you need to be an advanced presbyope to need computer glasses, and age 50 and/or +2.00 is the right cut-off.

If you're talking about intermittent blur or the dreaded "eyestrain/tired eyes" thingy, then a low add is nice for just about anyone.

[DanLiv]

The goal power at the fitting point in the Computer and Workspace is 50% add, and as opposed to the older Office design they are made in 0.25D degression increments.

The degression thing is annoying when customers need not-50% computer powers. I have to manually fudge the ordered Rx to produce the results I want. E.g. if a plano +2.00 add wants +0.75 instead of +1.00 at computer, I can either lower the seg a few millimeters, or input the Rx to the lab as -0.50 distance and +2.50 add to get the desired powers. Seems like unnecessarily convoluted work. Why can't I just order the fitting point power and the near total power I want and the lens gets designed to to make it happen. I can only presume taking away such flexibility is an effort to reduce remakes from inexperienced opticians ordered incorrect powers willy-nilly.

[Uilleann]

Inexperienced opticians - and ODs MDs.

What the decades have shown me is that with very and I mean *very* limited exceptions, that almost every patient does perfectly fine with the lab conversion from their full distance Rx and add supplied. The ones that don't, do exist, but are really few and far between. The remakes will start rolling in however when the prescriber is trying to do anything "fancy" with the typical power/digression designs of the lenses. Probably best to resort to either a traditional PAL design, or any of the myriad "anti-fatigue" options out there in those cases. You'll have your precise Rx control, though possibly at the expense of width or near zone size of course.

[drk]

The degression thing is annoying when customers need not-50% computer powers. I have to manually fudge the ordered rx to produce the results i want. E.g. If a plano +2.00 add wants +0.75 instead of +1.00 at computer, i can either lower the seg a few millimeters, or input the rx to the lab as -0.50 distance and +2.50 add to get the desired powers. Seems like unnecessarily convoluted work. Why can't i just order the fitting point power and the near total power i want and the lens gets designed to to make it happen. I can only presume taking away such flexibility is an effort to reduce remakes from inexperienced opticians ordered incorrect powers willy-nilly.

i know, right?

[AngeHamm]

What the decades have shown me is that with very and I mean *very* limited exceptions, that almost every patient does perfectly fine with the lab conversion from their full distance Rx and add supplied. The ones that don't, do exist, but are really few and far between.

In addition, the overwhelming majority of those exceptions involve patients with highly unusual, and usually quite impractical, office setups.

[mervinek]

In addition, the overwhelming majority of those exceptions involve patients with highly unusual, and usually quite impractical, office setups.

That's why there needs to be a conversation regarding working environment. A patient just saying they work on computers isn't enough. You need to ask questions. We sell a lot of Near Variable Focus lenses in our office and a lot of them are for artists and musicians due to working distances. We have a large success rate. The ONE time I had someone hate their NVF I was stumped...until he told me about his set up. He had multiple monitors and some at weird distances and locations. One was located very low (below desk height) and to his far right. What the heck! He also had one on a shelf above him. Nope. Not going to work. That was years ago and since then, I almost grill my patients on their working environment. I even tell some to come back with measurements if they can't remember.

[AngeHamm]

That's why there needs to be a conversation regarding working environment. A patient just saying they work on computers isn't enough. You need to ask questions. We sell a lot of Near Variable Focus lenses in our office and a lot of them are for artists and musicians due to working distances. We have a large success rate. The ONE time I had someone hate their NVF I was stumped...until he told me about his set up. He had multiple monitors and some at weird distances and locations. One was located very low (below desk height) and to his far right. What the heck! He also had one on a shelf above him. Nope. Not going to work. That was years ago and since then, I almost grill my patients on their working environment. I even tell some to come back with measurements if they can't remember.

When I came back into the industry in 2008 after a seven-year absence, one of my first patients was a violinist for the Richmond Symphony. She needed glasses for music stand distance. It was a crash course for both of us, but we got the RX right the first time.

[mervinek]

Most of my musicians are just using a music stand or are playing piano at home. I had a few that needed to see a conductor too, so you have to have that conversation... how far away is the conductor. How well do you need to see the conductor clearly... just the arm movements or the facial expressions as well? I think all my patients have been within the 8' range from the conductor so it wasn't much of an issue... but again... gotta get that information out of them!

On a side note.... it drives me nuts when people make "computer progressives" by using a progressive and just changing the rx to intermediate near. The lenses weren't designed for that. Use the correct lens people! Ok. Rant over.

[drk]

Mervinek, I agree, but with insurers penalizing some of these computer PALs (for no good reason that I can see) like, 80% U&C, where a standard PAL is $60 or something, it's going to happen.

[mervinek]

I get it...but I don't have to like it!

[Kwill212]

Most of my musicians are just using a music stand or are playing piano at home. I had a few that needed to see a conductor too, so you have to have that conversation... how far away is the conductor. How well do you need to see the conductor clearly... just the arm movements or the facial expressions as well? I think all my patients have been within the 8' range from the conductor so it wasn't much of an issue... but again... gotta get that information out of them!

Orchestra players are a perfect case for, and my only ever use of executive bifocals. Just a sliver of conductor distance in the top with a seg height well above pupil. Nearly full lens clarity for the music stand and no head movement required whatsoever to switch between music stand and conductor.

On a side note.... it drives me nuts when people make "computer progressives" by using a progressive and just changing the rx to intermediate near. The lenses weren't designed for that. Use the correct lens people! Ok. Rant over.

I love the IOT suite of office/computer lenses and I think they work great. But you can also make a great pair of cubicle type glasses with a standard progressive and the appropriate power changes.

[drk]

Cubicles have vanished.

[Kwill212]

Yes, but people working for 8-12 hours at a time exclusively in a 3ft and closer environment have not.

[drk]

True. What should we call it? The metaverse?

[Uilleann]

On a side note.... it drives me nuts when people make "computer progressives" by using a progressive and just changing the rx to intermediate near. The lenses weren't designed for that. Use the correct lens people! Ok. Rant over.

I would agree. But when you get that stubborn prescriber who just has to have it THEIR WAY DAMNIT!!! You aren't left with many other easy options. Sometimes it's easier to just make a "whatever" and let the Doc deal with the possible remake. It's not ideal, nor even best practice - but it can also work, in all fairness - in extremely limited scenarios.

[Kwill212]

for the record I was quoting someone else in that reply. Not my words here ^^^^

[Uilleann]

for the record I was quoting someone else in that reply. Not my words here ^^^^

OOPS! Fixed. :D