Zoomerang Internet Questionnaire on power measurement practices

“Zoomerang” Internet Questionnaire on power measurement practices – Analysis of response by Optician Association of America (OAA) Feb 2008 data Dick Whitney (CZV) / Joe Dezenzo (Luxottica Retail) 03 -Mar-08

Optician Association of America (OAA) “Zoomerang” response to Questions on power measurement practices – Dick Whitney (CZV) / Joe Dezenzo (Luxottica Retail) üAt the Sept. 2007 ANSI Z 80. 1 meeting, the topic of ANSI /ISO power measurement practices and tolerances use was discussed üDick Whitney agreed to work on a questionnaire to determine industry practices in power measurement. Joe Dezenzo (Luxottica Retail) volunteered to assist. üIn Dec 2007, Dick drafted a set of questions and sent to Joe; Joe refined them and pursued on line “Zoomerang” method. üJoe worked with the Opticians Association of America (OAA) and got their agreement to participate in an Internet “Zoomerang” Survey. Their cooperation is most appreciated.

Optician Association of America (OAA) “Zoomerang” response to Questions on power measurement practices – Dick Whitney (CZV) / Joe Dezenzo (Luxottica Retail) The following 10 questions were asked of the OAA members: 1. ) What type of power measurement equipment is used in your facility? : a) b) c) d) Automatic Focimeter /Lensometer Manual Focusing Lensometer– Scale output Manual Focusing Lensometer – digital output Both Automated and manual focusing 2. ) What cyl mode is used for display? a) b) Minus cyl (-) Plus cyl (+) 3. ) If digital output, what increment readout (rounding) is used? a) b) c) d) e) none 0. 12 0. 25 Other Don’t know

Optician Association of America (OAA) “Zoomerang” response to Questions on power measurement practices – Dick Whitney (CZV) / Joe Dezenzo (Luxottica Retail) 4. ) What Standards or specifications do you use for RX power verification / acceptance? a) b) c) d) Internal / company specifications ANSI Z 80. 1 ISO 8980 Other 5. ) Where are these Standards or Specs located? a) b) c) d) Next to the Lensometer In a drawer Not sure Don’t have them 6. ) How long have you used these tolerances? a) b) c) Less than 5 years Six to ten years More than 10 years

Optician Association of America (OAA) “Zoomerang” response to Questions on power measurement practices – Dick Whitney (CZV) / Joe Dezenzo (Luxottica Retail) 7. ) What action(s) might you do you use if the lens has been found to be out of tolerance for power? a) b) c) d) Re-measure a second time on same instrument without moving lens Re-measure a second time on same instrument, moving lens Measure on another instrument Reject lens without re-measurement *8. ) Does your facility use a computer system to determine if the lens meets power tolerances? a) Yes b) No

Optician Association of America (OAA) “Zoomerang” response to Questions on power measurement practices – Dick Whitney (CZV) / Joe Dezenzo (Luxottica Retail) 9. ) Question asked: Do you tolerance the sphere and cyl meridians individually or the powers when checking the cyl? a) Sphere and Cyl =What is displayed on Automated Units and written in Rx’s b. ) Sphere / Cyl Meridians Both principle focus powers, cyl must be computed for manual focusing, cyl meridian must be computed for automated c. ) Don’t know = Perhaps the most honest answer!

Optician Association of America (OAA) “Zoomerang” response to Questions on power measurement practices – Dick Whitney (CZV) / Joe Dezenzo (Luxottica Retail) 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? a) b) Pass Fail

Optician Association of America (OAA) “Zoomerang” response to Questions on power measurement practices – Dick Whitney (CZV) / Joe Dezenzo (Luxottica Retail) Let’s review the outcome! Number of OAA participants= 331 in the following categories: Wholesale Lab 4% Retail Chain 20% 21% O. D. Office 18% 29% M. D. Office 8% Private Optician Other, please specify

Optician Association of America (OAA) “Zoomerang” response to Questions on power measurement practices – Dick Whitney (CZV) / Joe Dezenzo (Luxottica Retail) Question 1 Response – Type of Instrument Automatic 19% Manually focusing 65% Manually focusing digital Both 3% 32%

Optician Association of America (OAA) “Zoomerang” response to Questions on power measurement practices – Dick Whitney (CZV) / Joe Dezenzo (Luxottica Retail) Question 2: Cyl Mode output (where it applies) Minus cyl (-) 82% Plus cyl (-) 18%

Optician Association of America (OAA) “Zoomerang” response to Questions on power measurement practices – Dick Whitney (CZV) / Joe Dezenzo (Luxottica Retail) Question 3: Increment rounding (where it applies) None 27% 0. 12 35% 0. 25 23% Don't know 7% Other 8%

Optician Association of America (OAA) “Zoomerang” response to Questions on power measurement practices – Dick Whitney (CZV) / Joe Dezenzo (Luxottica Retail) Question 4: What Standards / Specs do you use? Internal / Co Specifications 14% ANSI Z 80. 1 83% ISO 8980 0% Other 3%

Optician Association of America (OAA) “Zoomerang” response to Questions on power measurement practices – Dick Whitney (CZV) / Joe Dezenzo (Luxottica Retail) 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%

Optician Association of America (OAA) “Zoomerang” response to Questions on power measurement practices – Dick Whitney (CZV) / Joe Dezenzo (Luxottica Retail) 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%

Optician Association of America (OAA) “Zoomerang” response to Questions on power measurement practices – Dick Whitney (CZV) / Joe Dezenzo (Luxottica Retail) 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%

Optician Association of America (OAA) “Zoomerang” response to Questions on power measurement practices – Dick Whitney (CZV) / Joe Dezenzo (Luxottica Retail) * Question 8: Do you use a computer to see if the lens meets your power tolerances? Yes 7% No 93%

Optician Association of America (OAA) “Zoomerang” response to Questions on power measurement practices – Dick Whitney (CZV) / Joe Dezenzo (Luxottica Retail) 9. ) Intended question: Do you tolerance both the sphere and cyl meridians along with the cyl, or just sphere and cylinder? Just for review: <= Meridian 1 Image Meridian 2 Image Sphere image (equally focused lines) Cyl (written in Rx and displayed on automated focimeters) = Sum of Mer 1 and Mer 2 Measured values; it does not have an image!

Optician Association of America (OAA) “Zoomerang” response to Questions on power measurement practices – Dick Whitney (CZV) / Joe Dezenzo (Luxottica Retail) Question 9: What meridians / values do you tolerance? Sphere and Cyl separate 76% Both Sphere/Cyl Meridians 22% Don't know 2%

Optician Association of America (OAA) “Zoomerang” response to Questions on power measurement practices – Dick Whitney (CZV) / Joe Dezenzo (Luxottica Retail) 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….

Optician Association of America (OAA) “Zoomerang” response to Questions on power measurement practices – Dick Whitney (CZV) / Joe Dezenzo (Luxottica Retail) It depends on what tolerances / specifications you are using… Question 10: Prescribed Rx: +0. 25=-3. 25 x 103 Measured Rx: +0. 37= -3. 18 x 103 For those 67% who would pass the lens, they are using “common US Industry practice” and neither ANSI 1995 / 2005 or ISO 8980…

Here is how “Common US Industry practice” would have passed the lens: n Record prescribed RX: OD: +. 25 = -3. 25 x 103 n Measure fabricated RX: n n n 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 one might fail the lens using ANSI standards since 1995 (~ISO) 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 Z 80. 1 because of strongest meridian error, but few labs ever apply this. It passes the common practice of tolerancing the sphere and cyl.

The ANSI /ISO method can only practically be used using a computer to calculate pass fail as it relies on tables like this: Recall that 93% of respondents did not use a computer at inspection. Could you figure the pass fail without a computer? ANSI / ISO table From their answer to question 10, 67% did not use the ANSI /ISO Method even though 83% said they did!

Optician Association of America (OAA) “Zoomerang” response to Questions on power measurement practices – Dick Whitney (CZV) / Joe Dezenzo (Luxottica Retail) Thanks to the OAA for their cooperation! It is proposed that other organizations take part in a similar study. Any comments or suggestions? Dick Whitney (CZV) / Joe Dezenzo (Luxottica Retail)