11-07-10

11-07-10Dick Whitney (Carl Zeiss Vision / ANSI Z80.1 Chair)

“ANSImplified” – A Practical Application of Z80.1

By Dick Whitney – Nov 7, 2010 MA Opticians ABO Course




Introduction & Personal Background

Present responsibilities

Global Standards Mgr – Carl Zeiss VisionChair of Vision Council Len Technical Committee since 1997Chair of ANSI Z80.1Chair of ISO 14889 Fundamental StandardDirector of AO/ Optical Heritage Museum

http://www.opticalheritagemuseum.org

Background

Born and presently live in SouthbridgeEmployed by AO/SOLA/CZV since 1974Began in Materials Testing Lab conducted physical and optical testing for AOQC work/ engineering for AOLITE CR-39 processLens Design –SF Aspheric Aspherlite &AO55Design implementation -AO Pro Easy , AO Compact

1954

1:05Dick Whitney (Carl Zeiss Vision / ANSI Z80.1 Chair)



Course topic outline

1.ANSI Z80.1 Prescription Lens Standard scope / purpose/makeup of experts – 5 min

2.General History of Standard- 5 min

3.Must I comply?- 5 min

4.What’s new ? 5 min

5.ANSI Research for this revision – 10min

6.ANSI 2010- Compliance with Power tolerances just got easier – 10 min

7.ANSI Cyl Axis tolerances of 2005 and 2010 – adopted by ISO - 5 min

8.What about the next revision – any suggestions? 3 min

9.Feedback / Questions / comments – 2 min




1. ANSI Z80.1 Prescription Lens Standard scope / purpose/makeup of experts – 5 min

Dick Whitney (Carl Zeiss Vision / ANSI Z80.1 Chair)



1. ANSI Z80.1 Prescription Lens Standard scope / purpose /makeup of experts – cont




1. ANSI Z80.1 makeup of experts from 18 org




2. General History of Standard- 5 min

Historic ANSI Z80.1 Spectacle Lens Documents:

In 1956, the ANSI Z80 Standards Committee for Ophthalmic Lenses was organized. First Standard applying to lenses and included mounting tolerances was issued in 1964

ANSI Z80.1 - 1964 Cr. Carl R. Rudolph - Chairman ANSI Z80.1 - 1972 Arthur H. Keeney - ChairThe 1972 Standard included "relaxed" tolerances for plastic and heat treated lenses. This version included tolerances for off-axis performance for SV lenses, which were subsequently dropped in the next revision. ANSI Z80.1 - 1979 Arthur H. Keeney - ChairShifted to Mass produced lenses, away from factory finished. The title was changed from requirement to recommendation.




2. General History of Standard- cont.

ANSI Z80.1 - 1987 Jeff Kosh- ChairMore definitions, tutorials, and UV absorbance in lens materials addressed. ANSI Z80.1 - 1995 Jeff Kosh - ChairAdopted ISO power tolerances by each meridian, which turned out to be a mistake that took 15 years to fully correct. ANSI Z80.1 - 1999 Jeff Kosh - ChairInitial changes that loosened, but did not eliminate ISO power tolerance approach. ANSI Z80.1- 2005 Dan Torgersen - ChairSignificant change to the Axis angle tolerance was made, toReflect capabilities without compromise to wearer. ANSI Z80.1 -2010 Dan Torgersen – Chair Published in July 2010




3. Must I comply?- 5 min

Since 1979, the ANSI Z80.1 standard has been a recommendation, not a requirement

They are recommended guidelines, which when followed will help to deliver quality product to the consumer.

It is highly desirable to strive to meet this standard, but strict compliance is not always possible as noted in the Purpose section of ANSI Z80.1 .

While ANSI is not a requirement , local and state laws may dictate otherwise (NJ, CA).

ANSI Standards bodies strive for minimum requirements, in order not to restrict trade or inhibit new and different technologies.




4. What’s new? 5 min

Power tolerance method revision: The 2010 standard applies tolerances to the measured sphere and cyl (- notation) for a given RX

As worn correction for Rx ‘s permitted A clarification was added to permit tolerancing of an RX to the as worn corrected value, rather than the Rx as written by the Doctor. It reads “For lenses produced with compensations to account for as worn correction, the tolerances in the tables in section 5.0 apply to those values specified by the manufacturer, and not to the prescribed RX.”

Relaxation of Cyl Axis tolerance for weak cyls (first adopted in 2005, reaffirmed and adopted by ISO

Adoption ISO 8980-4&5 into ANSI Z80.1 -2010 ISO 8980-4 (AR Durability test method) standard was adopted in full ISO 8980-5 (Minimum Abrasion resistance if claimed) was also adopted in full. If abrasion claims to a lens surface or surfaces are made, this test requirement must be satisfied.

Optician Association of America (OAA) “Zoomerang” response to Questions on power measurement practices –

Dick Whitney (CZV) / Joe Dezenzo (Luxottica Retail)

5. ANSI Research for this revision – 5 min The following set of slides were presented resulting from a study of Focimeter power measurement practices determined from a questionnaire that I developed and was circulated on line to the Optician Association of America (OAA).

The feedback from this study convinced the ANSI Z80.1 committee to change the standard to comply with these practices.



In Dec 2007, Dick drafted a set of questions and sent to Joe Dezenzo (Luxotttica) who agree to coordinate sending them out; Joe coordinated an on line “Zoomerang” internet questioning method.

5. ANSI Research for this revision – 5 min

At a the Fall 2007 ANSI Z80 meeting, Dick Whitney agreed to work on a questionnaire to determine industry practices in power measurement. Joe Dezenzo (Luxottica Retail) volunteered to assist.



Wholesale Lab

Retail Chain

O.D. Office

M.D. Office

Private Optician

Other, please specify

Let’s review the outcome!

Number of OAA participants= 331 in the following categories:

4% 20% 21% 18% 29% 8%



OAA (Opticians Assoc. of America) Reponse to Feb08 Zoomerang Questions

0%10%20%30%40%50%60%70%

AutomaticLensometer

Manual FocusingLensometer-Scale

output

Manual FocusingLensometer-Digital

output

Both Automatic andManual Focusing

Question 1- Type of Instrument

Question 1 Response – Type of Instrument

Automatic 19%

Manually focusing 65%

Manually focusing digital 3%

Both 32%




0%20%40%60%80%

100%

Minus cyl (-) Plus cyl (-)

Question 2- Cyl Mode output used

Minus cyl (-) 82%

Plus cyl (-) 18%

Question 2: Cyl Mode output (where it applies)




0%

10%

20%

30%

40%

None 0.12 0.25 Don't know Other

Question 3 - Instrument rounding used

Question 3: Increment rounding (where it applies)




0%20%40%60%80%

100%

Internal / CoSpecif ications

ANSI Z80.1 ISO 8980

Question 4- What Standard s or Specs do you use?

Question 4: What Standards / Specs do you use?

Internal / Co Specifications 14%

ANSI Z80.1 83%

ISO 8980 0%

Other 3%




0%10%20%30%40%50%60%70%80%

Next to theLensometer

In a draw er Not sure Do not have any onsite

Question 5- Where do you keep the Standards / Specs that you use?

Question 5: Where do you keep your Specs?

Next to the Lensometer 70%

In a drawer 19%

Not sure 5%

Do not have any on site 7%




0%

20%

40%

60%

80%

Less than five years Six to ten years More than ten years Don't know

Question 6- When was the last time you updated your tolerances?

Question 6: When did you last update your Specs?

Less than five years 72%

Six to ten years 8%

More than ten years 3%

Don't know 17%




0%10%20%30%40%50%60%

Re-measure onsame

instrumentw ithout moving

lens

Re-measure onsame

instrument,moving lens

Measure onanother

instrument

Reject lensw ithout re-

measurement

Other, pleaseexplain

Question 7- What Action(s) might you use if the lens is found out of tolerance?

Question 7: What do you do when lens is out for power?

Re-measure on same instrument without moving lens 33%

Re-measure on same instrument, moving lens 57%

Measure on another instrument 46%

Reject lens without re-measurement 13%

Other, please explain 15%




0%

20%

40%

60%

80%

100%

Yes No

Question 8- Do you use a computer to determine if the lens meets your power tolerances?

* Question 8: Do you use a computer to see if the lens meets your power tolerances?

Yes 7%

No93

%



9.) Intended question: Do you tolerance both the sphere and cyl meridians along with the cyl, or just sphere and cylinder?

Sphere image (equally focused lines)

<= Meridian 1 Image

Meridian 2 Image

Just for review:

Cyl (written in Rx and displayed on automated focimeters) = Sum of Mer 1 and

Mer 2 Measured values; it does not have an image!




0%

20%

40%

60%

80%

100%

Sphere and Cyl separate Both Sphere/CylMeridians

Don't know

Question 9- What Meridians do you tolerance?

Question 9: What meridians / values do you tolerance?

Sphere and Cyl separate 76%

Both Sphere/Cyl Meridians 22%

Don't know 2%




0%

20%

40%

60%

80%

Question 10- Would you pass or fail the RX?

Series1 67% 33%

Pass Fail

Prescribed Rx:+0.25 -3.25 Measured Rx: +0.37 -3.18

Question 10:

Prescribed Rx: +0.25=-3.25 x 103 Measured Rx: +0.37= -3.18 x 103

Would you pass or fail this lens for power?

So which answer is correct?

The Answer is….




0%

20%

40%

60%

80%

Question 10- Would you pass or fail the RX?

Series1 67% 33%

Pass Fail

Prescribed Rx:+0.25 -3.25 Measured Rx: +0.37 -3.18

Question 10: Prescribed Rx: +0.25=-3.25 x 103 Measured Rx: +0.37= -3.18 x 103

It depends on what tolerances / specifications you are using…

For those 67% who would pass the lens, they are using “common US Industry practice” and neither ANSI 1995 / 2005 or ISO 8980…

Record prescribed RX: OD: +.25 = -3.25 x 103

Measure fabricated RX:

Is sphere error > .13? Absolute difference is .12, therefore sphere power acceptable Is cyl error > .13? Absolute difference is .07 and axis is 103 as prescribed, cyl

is acceptable.

Therefore, the lens Passes for power inspection

Here is how “Common US Industry practice” would have passed the lens:

Here is how one might fail the lens using ANSI standards since 1995 (~ISO)

1 Record desired RX / Transpose if necessary 0.25 -3.25

Step Sphere Cyl

2 Measure lens / record reading 0.37 -3.18

3 Look up tolerance on Sphere power (Meridian 1) 0.12

4 Compute abs difference for sphere reading 0.125 Pass / Fail for sphere power error Pass

6 Look up tolerance on Cyl 0.12

7 Compute abs difference for Cyl 0.07

8 Pass / Fail for cyl Pass

9 Compute intended cylinder meridian power from sph / cyl -3.0010 Compute measured cylinder meridian power from sph / cyl -2.81

11 Look up tolerance on Cylinder Mer power (Meridian 2) 0.12

12 Compute abs difference for Cyl Mer reading 0.19

13 Pass / Fail for cyl meridian power error Fail

The lens fails ISO tolerances for a power that is not displayed on the Focimeter, but must be calculated. It is also a failure to ANSI Z80.1 because of strongest meridian error, but few labs ever apply this. It passes the common practice of tolerancing the sphere and cyl.




6. ANSI 2010 – Compliance with the power tolerances just got easier -




7. ANSI Cyl Axis tolerances of 2005 and 2010 – adopted by ISO - 5 min




8. What about the next revision – any suggestions?

9. Feedback / Questions / Comments ?




Thank you for your attention!!!

11-07-10

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