Optical Lenses: Quality Control Can Trip You Up

By Paddy Kamen


When a client walks out of a retail optical store wearing his new glasses, and trips and sprains his ankle, is anyone to blame? This is not a Zen koan but rather a question designed to get you thinking about quality control in a new way.

In this very real example, the gentleman sued both the dispenser and the laboratory that finished the lenses. Ralph Chou, Professor Emeritus at the School of Optometry and Vision Science, University of Waterloo, acted as an expert witness for one of the defendants in the lawsuit. “This was an incredible case of bad luck, combined with poor quality control,” says Chou. “The dispenser had accurately read and interpreted the prescription. The job went to the lab and at that level, they entered the cylinder axis wrong. The lens went through the production process and was made perfectly in accordance with the wrongly keyed-in information, and the dispenser did not verify the finished lenses. I pointed out to both defendants that each was at fault: one for the transcription error and the other for not verifying.”

Errors in lens manufacture, surfacing and dispensing are potentially serious and could result in injury, bodily discomfort (e.g. headache or neck problems) or poor performance at work – potentially affecting a wider circle of people.

How can optical professionals, who have a responsibility for the integrity of the end product, minimize errors? Quality control (QC) is the answer. But is it happening where you work?

At the retail level, quality control begins with a standard against which you measure the lenses that come into the store. The standard indicates an acceptable margin of error in filling the prescription. If you don’t use an agreed upon and well-established standard, you won’t know what the range of acceptable deviation from the Rx is. Are your professional staff checking every lens (even plano – more about that later) using established standards? If so, what standards are you using?

Common practice in Canada is to use the American National Standards Institute (ANSI) standards. Chou says this practice developed because most eyecare professionals (ECPs) learned about ANSI standards from American-published textbooks. The relevant ANSI standards for dress ophthalmics are ANSI Z80.1 (for lenses) and ANSI Z80.5 (for frames).

Why don’t Canadian ECPs use a Canadian national standard for dress ophthalmics?  It isn’t for lack of trying; two internationally respected Canadian professionals have devoted a collective 50 years of their volunteer time to trying to correct this situation.

Ralph Chou is chair of the Canadian Advisory Committee (CAC) for Technical Committee (TC) 94 SC6 of the International Standards Organization (ISO). This committee develops standards related to eye and face protection. He also chairs the Canadian Standards Association (CSA) Technical Committee on Industrial Eye and Face Protection, which has published standards for industrial eye and face protectors. Chou has been involved with standards for vision products for over 20 years.

Toronto-based optometrist Josh Josephson chairs the CAC for ISO’s Technical Committee 172 SC7. This committee develops standards for ophthalmic optics (contact lenses and lens care products, spectacle lenses and frames, intraocular lenses and ophthalmic instruments). Josephson is Canada’s appointed expert at the ISO meetings held internationally. He was originally appointed to this committee in 1984. Chou also sits as an appointed expert on this committee.

Both Chou and Josephson would like to see the ISO standards for dress ophthalmics adopted by all ECPs in Canada. Why do they prefer the ISO standards to the ANSI standards? There are four main reasons:

  1. Canadians are represented on ISO technical committees so this is in the interests of Canadian ECPs and consumers.
  2. The rest of the world is going the ISO way, including Europe, which adopts ISO standards as they become available and makes them legally binding.
  3. The optics industry is international, with most of the manufacturing done outside of North America. International standards are better suited to this global marketplace. Further, if a manufacturer wishes to export their product to an ISO member country, their product is only acceptable if it meets the ISO standards. All ISO standards have been approved by all ISO “P” member countries, which includes almost every country in the world.
  4. Having one uniform standard would help to avoid errors in the case where a lab uses one standard and the ECP uses another.

Josephson has been using the ISO standards in his six Toronto-area stores since they were created. When finished lenses arrive from the lab they are checked by the in-house lab manager before cutting, edging and mounting them into the frame. The lab technician then rechecks the lenses. When the finished product is delivered to one of the Josephson stores the lenses are checked again by a licensed optician. “Checking should consist of verifying the prescription and the optical centration at the very least,” says Josephson.

There are serious client and business risks associated with inadequate or incorrect quality control. Aside from a lawsuit, which could devastate your business, there is also the matter of negative word of mouth when dissatisfied customers complain to friends, family, colleagues and neighbours. “The ECP is the final line of defense to make sure patient gets the right lens,” says Chou.

Chou strongly recommends checking on even plano lenses, based on an experience he had in 2005. He and a colleague in Australia ordered a large quantity of plano lenses from various manufacturers for a research project. When doing his due diligence by confirming that the lenses received were what he had ordered, he found that while the thinner lenses were generally fine, the thicker ones had a high error rate; many were not plano at all. He published an article on this in the professional journal Clinical and Experimental Optometry.

Tony Civello, president of Toronto-based C&C Optical Laboratories says that the quality of lenses he receives from manufacturers has improved dramatically since the time of Chou’s research in 2005. “It’s like night and day in the last ten years. Now when I do my final inspection for quality control I seldom find errors.” Civello attributes this to the superior technology used in lens manufacture today.

An important point for ECPs is the level of training achieved by the staff doing the quality control. Civello says that the better trained the staff is, the better your quality control will be. He feels strongly that optometrists, working together with an optician and the optometric assistant comprise the ideal practice team; even then, additional laboratory training is highly recommended. “This kind of exacting work requires highly trained individuals who will ensure that the eyewear prescribed by the ECP is the eyewear the patient gets,” he explains.

Josephson says that only licensed opticians or optometrists should quality control any product prior to dispensing and that the standards must be used consistently and observed exactly.

Chou agrees and he wonders how many optical retailers actually verify the parameters of lenses they receive. “That’s how I was trained and I know we teach it, but how many actually do it? I don’t know, but I’ve seen a couple of instances over the course of a few years in which there was no quality control and that tells me I’m looking at the tip of an iceberg. When it comes to liability for inappropriately made lens prescriptions, adhering to a standard and having the documentation that confirms you did it is your first line of defence. But you have to use it consistently in order to have credibility should someone sue you.”

Tips for Optical Retailers

  1. Hire qualified people to do your in-house quality control and make sure they are well trained. Make sure everyone knows about it, and use it on every lens that comes into and leaves your place of business.
  2. Keep accurate records of your quality control process on each lens.
  3. Ask your professional association to require a specific standard (preferably ISO) for your profession, if they don’t already.
  4. Make sure those doing quality control have their own vision appropriately corrected. Josh Josephson had an experienced and reliable LAB person begin making QC errors. Upon investigation, Josephson realized that the chap needed to update his own prescription. How ironic!

What’s New in Lens Designs and Technology?

Smoother transitions in progressives and improved peripheral vision are two of the key features to watch for in new ophthalmic lens designs. Let’s have a look at what’s new from our leading lens manufacturers along with some sunwear manufacturers who create proprietary lens materials.

Dossier_HoyaHoya has three new lens categories on offer. The iD LifeStyle 2 is a freeform progressive. The vertical and horizontal components are split between the front and backside of the lens. There are two styles: the Clarity is best for a newer progressive wearer and the Harmony offers greater precision in the near-portion for the mature client. With even distribution of power changes, the lens provides smooth interaction between far and near vision when multi-tasking.

The Hoyalux ARRAY is an affordable and versatile freeform design in a full backside progressive design and anti-reflective (AR) technology. Available in a wide range of materials, including a polarized option, the ARRAY provides the best visual acuity, optimized for every patient.

The Recharge EX3 is an enhanced-contrast lens that reduces blue light by 10 per cent compared to conventionally treated AR lenses. This lens helps to reduce symptoms of digital eyestrain, while also being oil-repellent for easy cleaning. 

With the recent introduction of the Stylistic™, Essilor becomes a company knownDossier_Essilor for sun lenses. Stylistic is designed for large and wrap frames, in single vision and Varilux progressive designs.

“Before the Stylistic it wasn’t possible to have perfect corrective vision in the really large frames, because there wasn’t the diameter capability,” says Julie Cornish, senior brand manager, sunwear. Stylistic benefits from Essilor’s W.A.V.E Technology2™, which manages higher order aberrations for great contrast and image sharpness.

Stylistic is available in clear, Transitions or sun lenses in a wide range of base curves, and is further enhanced when combined with Crizal® for maximum UV protection.

In another innovative move, Essilor has partnered with Transitions Optical to develop the new Transitions® SignatureTM VII lenses in a graphite green colour. This lens echoes the 1950s when green was applied to sunglasses worn by U.S. Navy pilots to help them track objects against a variety of outdoor backgrounds.

Providing the truest colour representation for more natural vision and enhanced contrast, graphite green is the result of Essilor’s research. Combined with Transitions Chromea7™, this new lens is a winner indeed, and available exclusively via the Essilor network. This tint will appeal to the young urban adults who adore retro fashions.

Dossier_BolleBushnell brings the Genus from Serengeti to the sunwear market with a lens that is 75 per cent lighter than glass and 10 per cent lighter than polycarbonate. Made from Trivex material, built with NXT technology, this lens is also photochromic and polarized.

Bushnell also supports cyclists with a wide field of vision on the Bollé® 6th Sense and Breakaway. The shape of the lens on the 6th Sense is designed to adjust to the cyclist’s position by extending the vision area vertically, while also extending protection to the eye. Both models hold the promise of no-fog on the lens, ever. This hydrophobic, oleophobic and photochromic lens can be produced for prescription wearers while being lightweight for all-day wear.

Transitions Optical employed its Life360™ product development model to create Dossier_Transitionsthe Signature VII lens to be highly responsive in a number of real-life lighting situations, including extreme temperatures. An exclusive dye – Chromea7 – allows the lenses to be more reactive to indirect and reflected sunlight. They become even darker on hot days, combining outdoor performance with indoor clarity. Transitions tested the new technology and found that eight out of 10 clear lens wearers rated the Signature VII lenses as better than their regular clear lenses. The improved colours of these lenses are also an asset: the grey tint provides true-to-life colour and the brown is the best contrast-enhancing lens Transitions has ever offered.

And don’t forget that clients want to be kept up-to-date on the latest technologies from Transitions: 62 per cent of consumers agree that knowing about technology improvements would make them more likely to purchase Transitions lenses. With the improved benefits and features of Transitions Signature VII lenses, the time is now to let clients know how their visual experience can be improved with Transitions.

Dossier_KaenonKaenon has created its own proprietary SR-91® lens material, which is polarized with their proprietary Glare 86® film. This lens is guaranteed for life against the cracking or splitting of the lens at drill-mounts, or the delamination of the inner polarizing film and the lens material.

The Kaenon SR-91 lens comes standard in all frames and is available in Rx. Kaenon’s unique tints – grey, copper, brown or yellow – maximize light transmission levels and improve visibility in any weather conditions or at any time of day.

And new from Kaenon is the Black Label collection, which features their darkest grey G12 lens.

Kodak Precise™ PB progressives control the surface power at virtually every pointDossier_Kodak on the lens. This fixed-corridor, backside lens gives a smooth power increase, with all viewing areas coordinating for a wearing experience that is closest to having perfect vision without glasses. Peripheral distortion is a thing of the past. This lens is also available in a short corridor design for small fashion frames.

Kodak Unique™ is a variable corridor, backside digital progressive that provides greater peripheral clarity and improved image quality in the principle viewing areas. The patient’s frame shape, monocular PD and fitting height are all used as data points for selecting the best corridor length. The Unique is available in more than 50 lens materials, for virtually any lifestyle or occupation.

Kodak lenses are available through Centennial Optical and Riverside Opticalab Group.

Dossier_SmithSmith Optics recently introduced the new ChromaPop™ Polar Blue Mirror and ChromaPop Polar Bronze Mirror lens tints to their collection of scientifically advanced polarized lenses. ChromaPoplens technology helps the brain recognize true colour, faster, regardless of lens tint. Both the fashion and sport needs of clients are addressed in different frame styles with plano or prescription lenses available. ChromaPop is especially designed for people playing and working on and around the water, giving them unmatched visual clarity.

Nikon’s Presio Master FP and SeeMax Master AP lens designs push the Dossier_Nikonboundaries of ophthalmic lens technology, resulting in a lens that virtually eliminates distortion in the area that typically generates the greatest discomfort: the periphery. Patients love having a wider usable lens area and noticeably sharper fields of vision.

Moving into the dedicated sun lens market, Nikon brings Radiance FP to the market. This dynamic lens offers the protection and comfort of polarization for almost any prescription and frame. Fashion and function combine with both grey and brown lenses available in single vision or progressive designs.

Dossier_Seiko‘Ultra-personalized’ describes the Seiko Superior lens from Plastic Plus, where company president Paul Fabish says, “I’m wearing the Superior and it definitely has the ‘wow’ factor.”

The three designs are: Superior B – a balanced, blended design; Superior N, with near-zone priority; and Superior F, with far-zone priority. The Superior is 25 per cent flatter in profile than other free-form designs. “I wear the Superior B and the majority of dispensers will use this design exclusively.  But the N is perfect for a draftsman and the F is great for landscapers or drivers.”

Maui Jim introduces the PureAir™ sunglasses collection, featuring MauiPure® lensDossier_MauiJim technology, for sunwear so light it feels like air. Billed as the world’s clearest non-glass lens, PureAir are the lightest lens in any Maui Jim sunglass, with patented PolarizedPlus2® elements to virtually eliminate glare and protect the eyes from all UV rays. Pure, vibrant colour is on view through the PureAir lens, as a result of the lens composition, which includes three rare earth elements, along with other proprietary treatments. Waterproof and oleophobic coatings add to the clarity of the lenses. Available in plano only.

Dossier_ShamirShamir presents the Shamir Duo™, a revolutionary new bifocal design that completely eliminates the distinctive line that previously defined bifocal lenses. “By introducing a Freeform® design, we are able to improve the optics and the cosmetic features, allowing for a variety of materials and treatments,” said Martin Bell, vice president of sales and marketing. “This makes the Duo superior to standard bifocals.”

A natural, distortion-free visual path is realized in the Duo. No longer do bifocal wearers have to give away their age with the look of their lenses.

Also from Shamir, the Attitude III® is a highly functional lens available in two progressive versions – Sport or Fashion – as well as single vision. The Sport design helps the wearer see the ground clearly several steps in front of them, in the intermediate zone (great for runners). Full near vision is also present. The Fashion design was created for large fashion frames, with an intermediate zone that enhances the viewing of tablets and smartphones, along with fully functioning near and distance zones. All Attitude III lenses are available in base curves up to +10,00 with fully corrected optics.