Interview with Dr. Markus Haidl, Vice President of Corporate R&D at Carl Zeiss Vision, on the new self-tinting PhotoFusion® lenses by ZEISS
ZEISS has a clear commitment to constantly ensuring that the products and services of the optics industry remain state of the art. That is why they developed and produced the self-tinting lenses for their latest product, PhotoFusion® in house. The PhotoFusion® lenses contain patented photoactive colour molecules that adapt to changes in light twice as quickly as existing photochromic lenses by Carl Zeiss Vision, allowing them to meet eyeglasses wearers’ demands for making everyday life easier.
Mr. Haidl, ZEISS has 160 years of experience in the field of vision. How much of this expertise went into your new product, the self-tinting PhotoFusion® lenses?
The extensive expertise we have at ZEISS was the very reason we decided to look at self-tinting lenses in the first place. The ZEISS portfolio already included self-tinting lenses, but for PhotoFusion®, we wanted to bring the technology up to ZEISS standards, too. With this aim, a highly driven, international team made up of staff from many different departments worked for more than two years on the new project. Eventually, our chemical and technical experts succeeded in combining the optics expertise, understanding of materials and affinity for technology of our high-tech corporation to produce PhotoFusion®, a pioneering development in self-tinting technology from ZEISS.
PhotoFusion® is based on innovative ZEISS technology that uses patented photoactive colour molecules. How does this work, exactly?
The photoactive colour molecules are complex chemical compounds that alter their structure and form when exposed to UV light. The lens forms the matrix through which the colour molecules are evenly distributed. When exposed to sunlight, the photoactive colour molecules depart from their normal structure, opening up and forming new bonds between moieties. This enables the colour molecules to absorb light and tint the lens so that it becomes darker. At times and in places where there is no UV radiation, like at night or indoors, the colour molecules return to their original structure and the lens becomes clear. The key factor required for the tinting to work properly is that the molecules have sufficient space in the matrix to alter their form and structure quickly. During development, we managed to find a matrix that perfectly accommodates the colour molecules. This is the only way to ensure that they have enough space to enable the lenses to tint and clear again very quickly when the light conditions change.
our aim is to accelerate the light reaction time even further, above all so that those wearing the eyeglasses can enjoy a better quality of life
PhotoFusion® eyeglass lenses adapt to changes in light conditions much more quickly than conventional photochromic lenses from ZEISS. How did you manage to achieve that?
Actually, one of our greatest challenges during development was to improve the speed at which the lenses become clear after tinting. It is important to realise that the tinting process is triggered by UV rays, which are rich in energy. The photoactive colour molecules absorb the energy, thus quickly altering their structure. The clearing process, during which the molecules return to their original structure, is triggered by a reduction in UV rays. This is a reversible process with a different energy balance, and the wearer perceives the process as taking a little longer. In addition to the improvement of the lens matrix I mentioned earlier, we have now also managed to alter the speed of the chemical reaction to the UV light so that the self-tinting effect is applied and removed much more quickly.
What does wearing PhotoFusion® mean to eyeglass wearers?
Eyeglass wearers immediately notice an improvement in quality compared to conventional products. The most obvious difference is the shorter reaction time – the colour molecules in PhotoFusion® lenses adapt to changes in light conditions much more quickly. Wearers also gain a great sense of security from the fact that PhotoFusion® lenses offer 100% UV protection at all times, regardless of the level of tinting. PhotoFusion®’s excellent colour stability is also very important to users – colour consistency is guaranteed when changing from light to dark and vice-versa. ZEISS PhotoFusion® lenses are available with grey or brown tinting; during the transition, the grey glass stays grey and the brown glass stays brown. At the same time, the lenses balance out the wearer’s colour perception. In short, the colour stability of PhotoFusion® gives customers eyeglasses that look great, and are great to look through.
Who are PhotoFusion® lenses aimed at particularly?
These lenses are basically aimed at anyone who wears eyeglasses and doesn’t want different pairs for indoors and outdoors or cloudy and sunny weather. From my own experience with PhotoFusion®, I can tell you that they really are very practical; the lenses change from light to dark and vice-versa more quickly than previous products. This means that I only ever need one pair of eyeglasses with me at any time, which makes everyday life much easier. The automatic tinting and 100% protection against UV rays also makes PhotoFusion® lenses perfect for people with sensitive eyes.
What developments do you expect to see for self-tinting lenses in the future?
Well of course, our aim is to accelerate the light reaction time even further, above all so that those wearing the eyeglasses can enjoy a better quality of life. Whether we can do that with the current technology, i.e. with the photoactive colour molecules, or if we need a completely different approach, will become clear over the next few years. We always base our actions on the philosophy that “after the launch is before the launch”. Whenever we launch new products on the market, they are planned out on a roadmap. This ensures that we never stop developing. As such, ZEISS is already working on further, continual improvements to the technology for selftinting lenses.
Dr. Markus Haidl, Vice President of Corporate R&D
Since 2008, Dr. Markus Haidl has been Vice President of Corporate Research and Development at Carl Zeiss Vision. In this position he is responsible for the research and development of eyeglass lens products. This encompasses the research and development of lens designs as well as the complete manufacturing value chain for ophthalmic lenses. Before he joined Carl Zeiss Vision in 2005, Dr. Markus Haidl started his career at Carl Zeiss in Oberkochen, Germany, where he was in charge of working on various cutting edge technologies as a Project Manager and then later as Head of R&D in the Ophthalmic Lens Division. Dr. Markus Haidl holds a master’s degree and a PhD in Physics from the University of Regensburg, Germany.
For further information please visit www.photofusion.zeiss.com.
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