Focusing on Natural, Healthy and Clear Vision

_{Article first published: June 2023}

Since its foundation in October 2013, the ZEISS Vision Science Lab has been conducting research into the physiological neurosciences and optical principles of human vision, and regularly publishes its findings on the key aspects of its work: myopia, presbyopia, visual rehabilitation and (trust in) Artificial Intelligence. Time to visit the research lab and take a look behind the scenes.

"'Enabling natural and enhanced vision' is the motto adopted at the time of the lab's foundation and we have remained true to this ideal right up to the present time," explains Professor Dr. Siegfried Wahl while opening a glass door labeled 'ZEISS Vision Science Lab' and entering a long corridor. On the left side there is a giant mural documenting the historic milestones of the ZEISS company, and on the right there is a series of laboratories. Dr. Wahl welcomes his team. Since the foundation ten years ago he has been in charge of the research facility, which is located at the Institute for Ophthalmic Research in Tübingen. Established as part of the Excellence Initiative sponsored by the German Federal Government and the federal states to foster science and research, the 'Industry on Campus' professorship has been managed jointly by Carl Zeiss Vision International GmbH and the University of Tübingen. "Our goals are, on the one hand, to create a natural vision experience with eyeglass lenses, and on the other hand to conduct research into the conditions needed for clear, healthy vision and its development," explains Dr. Wahl. "Spanning both these goals is the fundamental understanding of visual perception, as apart from ophthalmology, the University of Tübingen is particularly recognized and renowned across the world as a leader in the neurosciences. There are still many questions about the complex eye-brain-system and the individual factors of human vision that need to be better understood."

It all started with a team of three people. In addition to Professor Dr. Siegfried Wahl, Dr. Katharina Rifai and Dr. Arne Ohlendorf have been involved with the ZEISS Vision Science Lab from the beginning. Today the facility employs about 20 people. With a total of nine post-doctoral research scientists, as well as several PhD students and undergraduates the international team has a solid foundation. They are all working on 'application inspired research'. "For every research idea, there must be a clinical need and a product vision, from which the research question is inspired that substantiates the product," describes Dr. Wahl.

"We adopted one of the first systematic analyses of eye movements for eyeglass lens design when developing the ZEISS DriveSafe eyeglass lenses specifically for driving," recalls neuroscientist and physicist Dr. Katharina Rifai. Currently she is in the laboratory performing eye tracking recordings in one of a total of six laboratory rooms at the ZEISS Vision Science Lab: A test subject sits in a chair and looks at an image on a monitor. His chin is supported on a chin rest mounted on a table. A camera records his eye movements. Dr. Rifai stands next to him watching a second monitor analysing his eye movements. "We use eye tracking both in the laboratory and a variety of behavioral situations in our research into visual behavior. In this way we can for example draw conclusions about which areas of an eyeglass lens are used in which visual situations."

This research approach was also applied in the study aimed at developing an eyeglass lens specially for drivers. The study used special cameras to record the eye movements of test subjects when driving in a real life scenario. "A number of different signals were recorded during the trip, for example videos of the driver's face and the environment observed when driving. By using eye tracking technology movements of the driver's head and eyes were extracted. The combination of head and eye movements is important for eyeglass lens design as this combination determines how the lens is used," explains Dr. Rifai. "A further example of view-optimized design is the ZEISS SmartLife eyeglass lens. Eye tracking eyeglasses were employed to identify special areas of the lens used during cellphone usage in everyday situations," she explains. The lens designs ZEISS DriveSafe and ZEISS SmartLife, which were developed from the findings of these studies, have been successfully established in the market.

Another laboratory just along the corridor is the Visual Optics Lab. Here, a test subject sits in front of an ophthalmic imaging instrument for optical coherence tomography, otherwise known as an 'OCT instrument', and looks into the instrument with one eye. Dr. Katharina Breher, a specialist in physiological optics, stands next to the instrument watching its monitor and analyzing the image it has created. This image shows the eye's retina and the choroid located behind the retina. "The choroid is a biomarker. The reason is that it consists of a tissue that reacts very quickly to external influences," states Dr. Breher. "This property, which makes it possible to reduce the time frame needed for studies, is very helpful when testing a range of eyeglass lenses such as myopia control lenses. This is particularly advantageous in the clinical environment." The examination of the choroid is just one example of the many different myopia research techniques to be found in the ZEISS Vision Science Lab.

Myopia has been one of the most important research fields since the lab was established ten years ago. Dr. Arne Ohlendorf, a research scientist specializing in myopia development, emphasizes this point: "Even before the lab was established, ZEISS worked together with experts drawn from myopia research so that ZEISS was in a position to offer eyeglass lens solutions customized to meet specific needs. Myopia has been one of the central research areas at the Institute for Ophthalmic Research in Tübingen for several years, which enabled us to work closely with them right from the start."

As a result of the increasing prevalence of progressive myopia, research into this condition has become much more relevant, particularly in recent years, and is now a subject attracting world-wide attention. This form of short-sightedness usually occurs in early childhood and can continue into early adulthood. Pronounced growth in the length of the eyeball is often the cause. Although progressive myopia cannot be halted, growth of the eye can be slowed. In addition to measures such as regularly spending time outdoors and reducing the amount of near-vision tasks, special eyeglass lenses and contact lenses in particular can make an important contribution to the proper development of the eye. While the progressive form of short-sightedness is indeed predominant in Asia at the present time, a significant increase in the frequency of this type of short-sightedness has also been observed elsewhere. That's why this year ZEISS launched ZEISS MyoCare, a myopia control lens, in Europe as part of ZEISS Myopia Management.

The ZEISS Vision Science Lab was involved in the development of ZEISS MyoCare eyeglass lenses right from the start. "When developing new eyeglass lenses such as myopia control lenses, we work closely not only with our colleagues in ZEISS Vision Care but also with international scientific institutions and eye hospitals," explains Dr. Ohlendorf. Examples of such collaborations are the long-term study with the University of Leipzig (the 'LIFE Child' study), joint clinical studies with the University Eye Hospital of Wenzhou in China and research partnerships with the University of Murcia in Spain. One of the results is the recent joint development with Professor Pablo Artal of the University of Murcia of a new instrument based on spatial light modulation technology. The instrument made the optical quantification of eyeglass lenses for the treatment of progressive myopia possible for the first time under real viewing conditions – a success story that merited publication in a prestigious journal.

As well as studies aimed at developing new eyeglass lens designs, the research institute also conducts validation studies of ophthalmic measuring instruments. These studies also form part of the responsibilities of the Visual Optics Lab where some of the ophthalmic measuring instruments designed by ZEISS such as the ZEISS VISUFIT 1000 or ZEISS i.Profiler plus for objective refraction stand alongside the OCT instrument. The specialists of the ZEISS Vision Science Labs and the Vision Technology Solutions Department of ZEISS Vision Care work closely together on validation studies for new ophthalmic measuring instruments developed by ZEISS. The requirements placed on the new instrument are formulated by the Vision Technology Solutions team, after which a study is designed and conducted by the ZEISS Vision Science Lab. Every ophthalmic measuring instrument developed by ZEISS goes through this extensive testing procedure in this scientific facility as early as the development phase and is also validated well before market launch.

In addition to the the premises in the Institute for Ophthalmic Research, the ZEISS Vision Science Lab is also represented in the Artificial Intelligence Research Building in Tübingen. Here, under the direction of Professor Dr. Siegfried Wahl, the team concentrates its research activities on three major topics: (trust in) Artificial Intelligence, smart algorithms for eyeglasses with electronically modifiable properties and a universal Artificial Intelligence interface for robust brain-computer or man-computer interaction. The prediction of behavior and use of the eyes as a window into the brain are of great importance in this work. "In our research we are looking at opportunities for offering people an enhanced quality of life through the use of Artificial Intelligence. A further goal of our research is to increase confidence in systems with Artificial Intelligence," explains Dr. Wahl. The technologies are tested in complex studies involving test subjects and patients.

Even if it sometimes appears that there is little scope left for research into human vision, this is not the case. "There is a surprisingly large number of aspects of visual perception still to be resolved," according to Dr. Wahl. "We will not be short of research projects in the future."

• Interview with Dr. Katharina Rifai: Our eyes are always in motion
• Interview with Dr. Arne Ohlendorf: We are not born with perfect vision
• ZEISS Eyecare Research Center Honored