Manufacturer's Forum

Report 2017 - Wavelength control

The Vision Expo East (VEE) in New York in 2016 was dominated by a physical problem, which in the past played a secondary role in the discussion among physiologists. Everyone knows that Blue light can cause negative changes in the retina of the eye in the light spectrum of the wavelength of 400 to 500nm – in the worst case this radiation can be responsible for Age Related Macular Degeneration (AMD).
Against this backdrop, the MAFO editorial team decided to hold the latest edition of MAFO – The Conference under the motto, ‘Blue lightis all around’. Four lectures were focused on this problem from different directions.
A clear rule when organizing a congress is that the highlight should come at the end in order to stop people dropping out as far as possible before the end of a long day. But what should an organizer do when more than one distinguished speakers come up with exciting topics? This is just what happened on the 24th February at the NH Hotel in Milan. The solution was to put one top lecture at the start of the day, to grab people’s attention, and the other at the end, so that the conference would finish on a high note.
By Jörg Spangemacher

Design of aspheric lenses

Mo Jalie started the conference off, explaining how to design aspherical lenses. A dry subject, one might think, densely packed with mathematics and physics. But as always Mo Jalie got to grips with this potentially boring subject, making it easy to understand the fundamentals; almost without mentioning mathematical and physical formulas.
Aspherical surfaces are employed because the surface itself is astigmatic and the surface astigmatism is used to combat aberrational astigmatism due to oblique incidence. The use of an aspherical surface gives the lens designer a new freedom to design spectacle lenses without the restrictions imposed by spherical surfaces. In his presentation Mo Jalie described the various types of aspherical surfaces and how the surface astigmatism arises before considering how to calculate the required asphericity and how this feature is used to produce flatter, thinner lenses.
In the case of astigmatic prescriptions, the surface requires different asphericities along its principal meridians and the geometry of these atoroidal surfaces, and he also described their use in the design of bi-aspheric lenses.

New technologies help to exploit the potential of the spectacle lens market

The second lecture represented an abrupt transition from the world of optics to the reality of the markets and their global development. Gianni Cossar, Global Director Optics & Eyewear, and Till Herzog, Senior Business Group Manager, reported on new approaches to exploiting new potentials in the spectacle lens market. Both lecturers work for GfK, the world’s fifth largest market research organization which was recently taken over by the investment group KKR.
Optics is fundamentally a complex environment because it includes three different businesses. But all three have one thing in common – a unique selling place – the opticians’ shop. What happens there? France with sales of € 3,990 million is the largest market in Europe, followed by Germany (3,262), Italy (1,330), Spain (1,115) and the Netherlands (652).
The comparison between the markets of Europe (France, Germany, Italy, Spain, Netherlands), Russia and Shanghai is fascinating too, whereby one startling fact is that the City of Shanghai on its own is larger than many countries in Europe.
Viewed from this perspective, the figures give a very interesting impression: Europe; Russia and Shanghai together as a whole and separately shown in brackets (Russia; Shanghai).
- Number of spectacle lenses sold (in thousands):
  96,336; 21,492 (Ru: 10,166; Sh: 11,326)
- Sales (€ million):
  10.351; 946 (Ru: 255; Sh: 691)
- Sales price (€):
  107; 86 (Ru: 25; Sh: 61).

Overall, it can be said that there are major differences in sales performance of the various countries as far as spectacle lenses are concerned. Sales in Spain fell by -0.7% last year and by -2.5% in France, while sales grew in the Netherlands by +3.7%, in Germany by +3.2% and in Italy by +2.4%, based solely on the increase in the average price. Two-thirds of all lenses sold last year were single-focus lenses while a third of all lenses were progressives with an increase of 4.1%. Two- or three-strength lenses hardly feature in the survey.
Irrespective of the type of lens, there is a clear trend towards higher refractive materials. Refractive indices of 1.5 to 1.59 represent a share of 64%; 1.6 to 1.66 just under 30%, an increase of 2.2%; and while lenses of even higher refractive indices have only a small market share of 6.9% they had a significantly higher increase of 3%, thus leading to an overall increase in the average price of a lens.

Wavelength control technology for healthy eyes

In the talk on this topic by Wim Bos, the audience was introduced to the key theme of the Congress the day before the Mido. Wim Bos is a lecturer who at MAFO – The Conference in the past has always been listened to attentively. In the meantime he now works for Mitsui.
There they have developed the raw material for ophthalmic products that absorb part of the High Energy Visible (HEV) segment of visible light, in particular in the range of 400 to 420 nm, in addition to UV light. The technology has been designed to be incorporated in ophthalmic lenses in a way that provides for a neutral colored, clear and aesthetically pleasing appearance. Several studies carried out on the effects of HEV light on the retina have suggested that cutting Blue light may help to maintain healthy eyes.
The Mitsui technology enhances aspects of the ‘blue cut’ technology based on coatings in which Blue light is reflected. In the product, the in-mass technology leads to the absorption of a considerable proportion of HEV. Due to its unique in-mass technology, it can be combined with the blue cut coating technology in one system. This makes it possible to reduce Blue light to the desired levels. The notion of protection beyond UV400 – which is currently widely accepted – to UV420 seems to be important for providing even greater protection for our eyes.
Wim mentioned that the Blue light hazard is often cited in relation to digital gadgets. However, Blue light is a part of the High Energy Visible light which exists in sunlight too. The peak wavelength emitted by digital devices is generally around 455 nm.
UV+420cut does not provide enough blocking for this range of Blue light, hence it is recommended to add a Blue light reducing coating on the lens using UV+420cut technology.

The science of Blue light

It is always interesting to observe the differences in presentation style between European and American speakers. With speakers from the other side of the big pond, there is always a bit of PR mixed in among the facts. Greg Naes of BluTechLenses is a smart representative and a speaker of conviction based on his familiarity with HEV light.
Greg said in today’s digital world we are surrounded by Blue light 24/7. The digital revolution has launched a global awareness of the visual and health effects of Blue light. At the same time patients have been exposed to a wealth of information which while it may be ‘marketing correct’ it is not necessarily ‘medically correct’. As a result of a certain amount of misinformation, many patients have been lulled into a false sense of security when it comes to protection against Blue light.
Six years ago a revolutionary workshop attended by industry leaders examined facts vs. fiction, differences in Blue light solutions and clinical best practice to protect patients of all ages.
During his lecture Greg explained the differences between Blue light solutions which exist today and how they can impact on the challenges patients face. At the end of his talk, Greg Naes outlined those patient groups most in need of high levels of protection, along with proven clinical strategies which have been tried and implemented worldwide.

AR coatings for complete eye protection

Gero Bongiorno had the task of keeping the audience awake after the opulent lunch. But this was not difficult for the Head of R & D of the Coating Technology division at Satisloh.
Daylight is composed of 5% UV (300-400nm), 43% visible light (HEV and LEV) and 52% NIR (Near Infrared from 700nm). UVA is mainly absorbed by the eye lens. A portion of this can reach the retina, especially in children. HEV and LEV meet the retina, whereby the proportion of the Blue light is important for seeing the entire color spectrum. Nevertheless, the blue-violet light is the main risk factor because light of these wavelengths reaches the macula.
How can the eye be protected with spectacle lenses and what influence do the different types of lenses have on this? Plastic lenses (uncolored) absorb UV light. But reflections on the back of the lenses mean that UV light can still get into the eye. Tinted organic and photo chromatic sunglasses do not help because the pupils open due to the darkened light.
There are two strategies for absorbing HEV. One is to coat both sides of the lens with a Blue Cut AR. This results in a clear blue reflection, which is particularly annoying with xenon and LED headlights of cars.
With the second option, the front surface is coated with a Blue Cut AR and the back surface with a standard UV AR. This results in a mixture of colors which is aesthetically less attractive.
Gero Bongiorno proposed the following solution to the problem: For the basic lens, a UV absorbing material should be used which is finished on the front surface with a Blue Cut AR and on the back surface with an UV AR. This combination provides low reflection in the highly sensitive part of the visible light spectrum.

Blue light induced retinal photo-ageing

Coralie Barrau, Research Engineer in Optics and Photobiology, heads a small scientific team at Essilor. Her research is centered on the photobiology of the eye, radiometry and interferential physics for new ophthalmic healthcare lenses. She is deeply involved in the collaborative research project between Essilor and the Paris Vision Institute.
Light synchronizes our biological clock like no other factor. Without light, our biological clock would shift by 33 hours within 60 days. This was the finding of an experiment carried out on himself by a young Frenchman who spent 62 days in a cave without daylight in 1962. This clearly showed that by day man needs blue-turquoise light.
But Blue light is an accelerating factor in retinal ageing and AMD. Retinal ageing is driven by oxidative stress in the outer retina. Oxidative changes in the outer retina are a hallmark of early AMD. The scientific rationale for Blue light induced toxicity on the outer retina (in vitro, in vivo, epidemiology). Blue light (380 to 500 nm) is one of the aggravating factors in AMD.
It would perhaps be too much to go further into this research work here.

IT architecture for industrial labs

There are always lectures at a congress where one cannot learn much which is new. The contribution of Jean-Paul Madaleno belongs to this category in the observer's opinion. He chose a very difficult and somewhat boring topic and gave a presentation on digital architecture such as can be found in many books. The fact that it can be transferred to other systems, when an appropriate interface has been defined and implemented is not really new, but due to the importance of the topic, sometimes it is a good reminder to have it pointed out.

Twilight Vision – Contrast – Glare: Fundamental physiological considerations

Fritz Paßmann, who teaches at the Handwerkskammer Dortmund, described glare as the mismatch between the eyes’ state of adaptation and the surrounding luminance.
His lecture focused on the physiological basis of contrast and glare. What influence can the lens manufacturer have on contrast sensitivity at dusk through appropriate surface design and coating?
In addition to the distribution of the photoreceptors on the retina, the rods increase towards the periphery to a maximum at about 15° and cones only in the macula. He drew attention to the important fact that the cones for short-wave light, increasingly present today in car headlights, occur at the edge of the fofea centralis. Both lead with oblique, incidental light to more sensitivity and to glare when there is too much light. This sensitivity is supported for short-wave light by the so-called Purkinje shift, in which the rods have their maximum sensitivity at about 507 nm. Glare is the mismatch between the adaptive state of the eye and the ambient luminance. An anti-reflective coating that reflects more in the short-wave range, as well as the new MR8 material which filters up to 420nm, should reduce this effect. In Fritz Paßmann’s opinion, however, many advertisements go way beyond the bounds of physics. Provocatively he ended his talk with the words, "Keep the marketing people in check!"

How to create market space in the optical industry?

This icing-on-the-cake from Mark Mackenzie was a worthy finale of a highly topical congress for the labs and the optical industry.
He referred to W Chan Kim's book, ’Blue Ocean Strategy’. Professor Kim teaches Strategy and Management at the ‘Insead’ business school in Fontainebleau, France. ‘Blue Oceans’ is the term used to describe strategies with which new markets are created. He described three steps:
1. Identify unspoilt markets
2. Generate demand
3. Protect this market so that potential competitors can be dealt with successfully.

As examples, Mark Mackenzie gave the introduction of digital surfacing and polishing at the turn of the century, as well as plastic lenses with the refractive index n = 1.56 and multifocal contact lenses, also explaining the background to these innovations.
Digital surfacing and polishing led to the development of progressives, which could be made where the position of the frame in front of the eyes, the life style of the wearer and/or the physiology of the wearer could all be incorporated into the design.
1.56 index organic lenses. This product, available in both clear and photochromic, appealed to consumers in poorer countries who wanted a thin lens at an affordable price. A pair of clear 1.56 index lenses is sold to the optician for between € 2.50 - € 5.00 and retailed to the consumer for between €7 - €10. In the Asia-Pacific region these lenses account for 79% of the market.
Appeal to the ageing population of contact lens wearers, as well as persons who wanted to continue with an active life style. There were between 500,000 and 600,000 multifocal contact lens wearers in 2015. EuromContact started recording multifocal contact lens sales in 2006.

Next year

Contrary to our original plans, MAFO – The Conference 2018 will again be held on the day before the Mido in Milan, on 23 February 2018.

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