Modern Lens Design

How eyeglass lenses become more and more individual

31 May 2023
Modern lens design

Article first published: May 2023

ZEISS SmartLife Individual 3 lenses offer the highest level of personalization available in a ZEISS lens. New scientific findings on visual behavior and the possibilities of digitalization form the basis for this individualization. Find out how modern lens design works.

Over the last 20 years, our lives have changed fundamentally. Digitalization became a big part of our everyday lives, smartphones have led to a complete shift in the way we work and function, and there has been a change in viewing behavior that extends across all age groups.

But just as daily life continues to change dynamically, research and development activities at ZEISS Vision Care and at the ZEISS Vision Science Lab, located at the University of Tübingen, continue to pursue the question of how to incorporate measurable changes in gaze behavior into the design and function of modern eyeglass lenses.

Dr. Christian Lappe

We live in an information age where visual content has become increasingly important. And we know that our brains address more than two-thirds of its cognitive power and processing power in a visual context. So, this has a tremendous impact on our perception and highlights the importance of the best possible vision, i.e. sharp, clear and fatigue-free.

Dr. Christian Lappe

ZEISS Expert

Collection of individual data: Media use, self-assessment and (visual) behavior

The more precisely the lens is adapted to the visual acuity and visual behavior of the eyeglasses wearer, the better the visual experience. So when it comes to manufacturing modern lenses, it is therefore enormously important to understand visual behavior and to deal with changing lifestyles and realities. This is the only way to create products that offer added value for eye care professionals and eyeglasses wearers. ZEISS researches human visual behavior in collaboration with various research institutions.

The international ZEISS Global Vision Study1, examined in 2020/21, among other things, how life and thus (visual) habits have changed in today’s modern, connected and mobile world. To gain more precise insights into visual behavior, millions of data points were recorded on the daily lives of several hundred people in different countries. The subjects belonged to different age and occupational groups and had different social and cultural backgrounds. Data collection took place at home, at work, on weekdays and on weekends. This diverse data allows for a patient-centered approach that attempts to capture the actual reality of people's lives.

Three important findings of the ZEISS Global Vision Study:

1. Age gives information about the visual needs
Regardless of age, interaction with digital devices has increased. Age-dependent similarities could be identified in the usage patterns. They allow us to dive deeper into the age structure and filter out age-specific details that make a difference. For illustration purposes, these were grouped into age groups.

Graphic showing how visual behavior differs between different age groups.

2. Self-assessment not sufficient for detection of visual needs
For the calculation of a modern eyeglass lens, the visual behavior is a central parameter. It is made up of various factors such as the type of activity and eye movement. The increasing dynamics due to parallel and competing attentions and activities, for example, paying attention to the path and the smartphone at the same time while walking, makes this a complex task and complicates the self-assessment of the relative and absolute proportions of engagement.

Graphic showing the discrepance between measurements and questionnaires.

3. Visual behavior is shaped by habituation
Comparing the study data with the data collected during the eye test, there is a difference between biological age and so-called ocular age or optometric status. This means that ocular status, visual needs, and satisfaction with a particular refraction are different than one would assume based on biology alone. These two factors must be considered to understand the spectacle wearer's habituation.

Portrait of the ZEISS Expert Manuela Weinreich

Experienced progressive lens wearers know for example that they have to look through the upper part of a lens to see in the distance, and through the lower part to see nearby. This means that the eyes and head behave differently compared to a more inexperienced progressive lens wearer who previously had the same prescription across the entire lens surface with single vision lenses. This is called habituation.

Manuela Weinreich

Responsible for product design at ZEISS Vision Care

Digitalization enables further individualization of lenses

An important component of increasingly individualized eyeglass lenses is a deeper understanding of visual behavior and oculomotor function. The fact that scientific studies can provide increasingly diverse data and, above all, that this data is becoming usable, is also thanks to the technological progress of intelligent measurement methods. "What's important here are the special technologies that help us advance science and knowledge,” explains Lappe.

ZEISS expert Dr. Christian Lappe wears a so-called eye tracker, which records eye movements and gaze direction. Such mobile eye trackers are used for objective data collection.

ZEISS expert Dr. Christian Lappe wears a so-called eye tracker, which records eye movements and gaze direction. Such mobile eye trackers are used for objective data collection.

The individualization of an eyeglass lens using ZEISS SmartLife Individual 3 as an example

To be able to use the findings of the Global Vision Study 2020/21, more than 12 million data points were clustered and evaluated using Big Data tools. A specially developed algorithm, known as Intelligence Augmented Design (IAD) technology, now enables the information to be transferred to the design of ZEISS SmartLife Individual 3.

The known parameters for ordering a ZEISS SmartLife lens, such as prescription, wearer and frame parameters, reading distance and age, are transferred to the IAD algorithm. This defines vision requirements and then optimizes the decisive design parameters based on the calculated object model and design fingerprints.

The object space model is the simulation of distances and viewing angles.

The object model is the simulation of distances and viewing angles. When adapting a ZEISS SmartLife lens to today's dynamic visual behavior, different distances and viewing angles are considered.

Graphic showing different design fingerprints for lenses.

Schematic representation of the improved distribution of visual zones adapted to individual visual behavior in ZEISS SmartLife Individual 3 lenses.

The design fingerprint or the so-called target design of an eyeglass lens defines the zones of clear vision that transition to the individual visual zones and out-of-focus visual areas on the lens itself. Different design fingerprints are optimized for specific purposes and individual preferences.

“The technology is called Intelligence Augmented Design because it does not replace refraction and questioning at the eye care professional’s. It augments human intelligence with the help of digitized automation,” says Dr. Philipp Jester, responsible for lens design at ZEISS Vision Care.

This means that even if two customers have the same prescription and the same order parameters, they can now receive different lenses adapted to their individual visual needs. "With ZEISS SmartLife Individual 3, we address the individual and not just data," says Weinreich. "Some eyeglasses wearers feel that a pair of glasses just doesn't fit them but can't specify it further. With the IAD algorithm, we can address needs that may not even be consciously described."

The calculation of a ZEISS SmartLife Individual 3 lens prescription in four steps:

Step 1: At the eye care professional’s, objective and subjective refraction is used to define the visual requirements and the appropriate lens. Here, all the necessary details for individualizing the lens are recorded: The frame data, the anatomical data such as the distance between the eyes, the refraction, and the type of lens: single vision, digital or progressive.

Step 2: The improved ZEISS SmartView 2.0 technology then forms the basis of the design: The technology considers the key elements of visual behavior and visual needs of people of all ages in today's connected, on-the-move lifestyle. In other words, the use of visual zones (near, intermediate, far), eye movements and head movements. This step already enables all-day comfortable vision at all distances and in every direction and is the basis of every ZEISS SmartLife lens.

Step 3: The individualization process starts here: The best fitting target for the lens design is created. This is done with the new IAD technology. In simple terms, the eye care professional's data – the specified lens type, the individual prescription, the wearer and frame data, and the person's age – are compared with the age-dependent visual behavior profiles in the database and appropriate optimizations are made. In this way, the optimal design target is selected.

Step 4: In this final step, all order parameters are used in an iteration process to adapt the real lens as closely as possible to the target design: The individual data of the spectacle wearer is thus considered in the calculation of the ideal lens surface. Once this step is complete, the final ZEISS SmartLife Individual 3 lenses are calculated, and the result is transferred to production.

Why individual lenses are worth it

The individualization of eyeglass lenses is not a new market trend. The continuously improved adaptation of eyeglass lenses to special visual needs can be seen as a result of technical progress. On the one hand, a different quality of data can be collected when conducting scientific studies, for example, through the use of eye trackers and other measurement sensors in the objective recording of oculomotor activity, i.e., eye movements and habitual visual behavior. In addition, computer-aided data analysis enables the processing and use of a much larger amount of data. On the other hand, intelligent algorithms help to bundle and analyze the findings and to translate them into concrete spectacle lens designs. The more precisely it is known how a eyeglass wearer looks through the lens with the respective spectacle frame, the more precisely the lens can be manufactured in such a way that it enables the spectacle wearer to see through it naturally. Optical vision support is thus received exactly where it is needed.

ZEISS SmartLife Individual 3 in numbers

Up to eight different technologies are combined for a ZEISS SmartLife Individual 3 lens:

  • Allows eye care professionals to better determine the near zone, promoting faster acclimation to new lenses.

  • Allows eye care professionals to tailor lens design to specific daily activities for further optimization.

  • Optimized for all-day visual comfort for a connected and on-the-move lifestyle.

  • Optimized near zone for better reading on digital devices.

  • The lens corridor is optimized to allow any choice of frame.

  • Adaptation to the personal visual behavior and requirements of the eyeglasses wearer.

  • Optimization of the final lens as close as possible to the target design and based on the selected frame and the anatomy of the wearer's face.

  • Takes average light conditions and the age-related pupil diameter of the wearer into account.

What that means for eyeglass wearers and eye care professionals:

  • With ZEISS SmartLife Individual 3 85 percent of wearers perceived wide fields of comfortable vision in all directions and at all distances.2
  • 8 out of 10 wearers adapted to their new lenses very fast.2
  • An up to 79 percent better match to visual needs and behavior.2
  • New ZEISS SmartLife Individual 3 lenses give up to 29 percent better performance.2,3

Four examples of how the individualization of the lens has been further developed at ZEISS:

2010: ZEISS IndividualFit technology

As early as 2010, the customer's visual needs, visual behavior and lifestyle were taken into account in the lens design for the first time. No eye trackers were used for the ZEISS IndividualFit technology yet. Individual data on anatomy and lifestyle through questioning, led to a specific lens design.

2014: ZEISS DriveSafe lenses

With the introduction of ZEISS DriveSafe lenses, fundamental changes in lens design occurred in 2014. The lens performance is task oriented as it supports the visual performance of the spectacle wearer while driving. Simulators were used to study eye movements during driving. Thus, for the first time, the design of eyeglass lenses was improved based on objective data.

2015: ZEISS Individual 2

With ZEISS Individual 2, the design of the progressive lens is adapted to the individuals main daily activities. The choice of three lens designs suits the wearer's needs. Optimization for the near zone and activities such as reading. Optimization for balanced vision for activities at a wide range of distances. And the optimization for dynamic vision at medium distances, such as for office work.

2018: ZEISS SmartLife lenses

ZEISS SmartLife goes beyond a specific, application-oriented approach as a portfolio for single vision, digital and progressive lenses. Based on scientific studies, the lenses are adapted to the visual needs of modern, dynamic and on- the-move lifestyles.

Press Contact Sarah Kopp

ZEISS Vision Care

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  • 1

    International Global Vision Study, Carl ZEISS Vision International GmbH, DE, 2020-2021. (Unpublished, data on file)

  • 2

    Market consumer acceptance test on ZEISS SmartLife Individual 3 lens portfolio with n=172 study participants in DE, IT, CN by Carl Zeiss Vision International GmbH, DE 2022. (unpublished, data on file)

  • 3

    In comparison with former ZEISS SmartLife Individual lenses.