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Hello,
I am doing some research and creating a "White Paper" on readers. Most of my testing has been done by basing the OTC readers vs. the ANSI Z80.1 Standard. Does anyone have a copy of the ANSI Z80.31 standard or can reference the "prescription" component of the standard?
So far, in my testing of 100 readers, 34 FAILED. I just want to compare the results vs. the ANSI Z80.31 standard and see if they would pass.
kdw613@gmail.com
Thanks!
You can buy a copy here:
https://webstore.ansi.org/Standards/.../ANSIZ80312017
ANSI is a private non-profit, and all their standards are copyrighted. The only legal way to own a copy of the official standard is to buy it. You can also borrow it from an academic library.
Readers are found to be fine and adequate by the public primarily because human vision is “squishy.”
Is "squishy" a technical scientific term, Barry?Quote:
Originally Posted by Barry Santini
Human vision is not "squishy". In fact, it's a supremely complicated and tremendously efficient process. (Yes, human visual perception is plastic/adaptable.)
OTC readers work based solely on their ability to deliver the necessary dioptric power for near point viewing with a minimum of optical unwanted effects.
How well do they work? Squishy.
Why?
1. The accuracy of self-selection of dioptric power is squishy.
2. The presence of uncorrected astigmatism or unequal refractive error makes the "averaging" process of selecting a supposed "best sphere" very squishy.
3. The production consistency of these commodities is "squishy" (see the nacent report above).
4. The quality of optics is "squishy".
5. The position of wear/lens centration is "squishy".
If you want an inconsistent, inexpensive, partially-effective solution to the problem with your amazing sense of vision, then squishy readers are for you.
(But pssst: you look like a cheapskate wearing trash glasses...)
(I feel like "plastic/adaptable" and "squishy" mean the same thing, but okay.)
With readers, we're talking acuity. That's not plastic.
With things like image size, prismatic effect, etc. that's plastic.
Acuity is absolutely plastic in practice. Different patients have very different tolerances for corrected acuity, for dozens of reasons, almost all of them bizarre and completely subjective. I've had patients reject new RXes that increase their acuity from 20/40 to 20/20 because "it's almost too sharp." I have patients who see 20/60 decline to fill a new prescription because "I see well enough." And I have others who reject a progressive because they can't read medicine bottle print out of the extreme outside corner of their lens. Human vision is squishy as hell.Quote:
Originally Posted by drk
Nope.
Acuity is acuity.
You can't fudge it. It doesn't increase or decrease (without some tangible reason). It doesn't vary. Look it up.
You're talking about weird patients and their own ideosyncratic behavior. And I've NEVER (and I'm old) have anyone tell me "Oh, I see too well with these glasses". Never.
And if some person with moderately reduced acuity "sees well enough" it's probably because they're being scared or cheap. Been there, done that.
I'm not lying or making things up, Doc. People communicate with opticians very differently than they communicate with doctors. I have at least one remake every year because the new prescription is "too sharp" or "almost too clear." Happens all the time.Quote:
Originally Posted by drk
I've had that happen myself, plenty of times. What takes them to 20/20 or their BVA is not always what they can tolerate in the real world. As a matter of fact I just had one this week-no lie! As soon as she put her glasses on she commented on how much sharper everything was but called me a few hours later to put her old lenses back in. (Yes, I'm aware that it takes longer than a few hours to adapt, but she'd had a considerable amount of change and wasn't going to be able to drive out of state adapting to the new lenses.)Quote:
Originally Posted by AngeHamm
It is to the best of my knowledge :biggrin:Quote:
Originally Posted by AngeHamm
Very true.Quote:
Originally Posted by drk
I couldn't count how many times I have had and seen this happen between myself and other colleagues over the years.Quote:
Originally Posted by AngeHamm
OK, let's go with that. Visual acuity is plastic.
That would mean, from your side of the argument, that as the patient's refractive error gradually increased and their visual acuity decreased, they adapted to it, because "plastic".
And presumbably they felt that they were seeing just great, and presented with no complaint whatsoever, but when the examiner found an increase in refractive error, prescribed a new correction.
Then, at dispense, the patient experiences a new, clear image, but doesn't like it.
Not necessarily that there is prismatic effect/curvature of field, etc. but it seems "too clear".
So...if it's plastic, then they wear them and they get used to the "too clear" just like they get used to all the prismatic effect, etc. too. Done.
What you're actually describing in my opinion is just ideosyncratic people with their way of describing their initial reaction to the lenses. Sure, we have to deal with odd people. Maybe the prescriber added a diopter of minus on a nuclear sclerosis patient, whatever. That goes to prescribing changes that patients can tolerate, not plasticity of visual acuity.
So you know, when I'm back there flipping lenses, they don't say: "Woah. That's really clear. Too clear. Back that down a little, sparky. There you go...I like that blurrier one."
They absolutely, absolutely, say that to me.Quote:
Originally Posted by drk
Malleable is a good word.
"Subjective, against all logic," as well.Quote:
Originally Posted by Lawman Nick
I'll have to agree with Drk on this one. I have never remade lenses for someone who's complaint was "vision is too good, too clear, too sharp" or anything of that ilk. I have had plenty of patients at dispensing make comments such as, "woah, things are so sharp, it's kind of weird." But literally never have they returned the next day, or next week, and stated that again. I would also surmise that if a patient does make a complaint of too clear or too sharp it is tied to some other change in the glasses that they don't know how to verbalize. Their new glasses are clearer but the fit is wrong so it's clearer but disorienting. They don't know it's because the tilt is wrong or base curve is different. They just know it's clearer but they don't like it. "too clear, switch me back to what was comfortable."
Returning to the original post we should all be aware that ANSI Z80.31 are not mandatory. They have no legal power and as such are "unenforceable". They are merely "suggested" tolerances for readers and Rx eyewear.Quote:
Originally Posted by kdw613
Hear's what I have always been told. As rbaker says "they are guidelines".....but if someone looses an eye from a broken lens the lawyers would be all over it asking why did you make/sell a product that did not pass ANSI standards? We are often asked by our 3 O's customers that their patient wants thinner lighter lenses, can I do it? I tell them you better have the patient sign a waver and even that may not help.Quote:
Originally Posted by rbaker
While ANSI Z80.31 is non-enforceable suggestion, it does state "All lenses shall conform to the impact resistance requirements of the Code of FederalQuote:
Originally Posted by rbaker
Regulations, Title 21 Part 801.410 (21 CFR 801.410). FDA 21 CFR Part 801.410 is enforceable law, and states that all "All lenses must be impact-resistant except when the physician or optometrist finds that impact-resistant lenses will not fulfill the visual requirements for a particular patient."
The ANSI standards I have(Z80.1,Z80.3, and Z80.31) all specifically reference this FDA code. So we can probably end the "ANSI isn't enforceable" semantics on the subject of impact resistance.
Do OTCs even come under ANSI? I'm guessing "no".
I doubt they're even considered "spectacles".
I think they're not covered by any regulation whatsoever.
Quote:
Originally Posted by drk
They are covered under the FDA
Code of Federal Regulations, Title 21 Part 801.410 (21 CFR 801.410).
That's beautiful; squishy, but beautiful