Guiding Principles on Accessible Products for the Visually Impaired

Felix Cordes

Jeremias Lange

Visual Design is not enough.

The more digitization advances, the more an excessive focus on the visual sense seems to emerge due to touchscreens, for example. People with visual disorders or blindness suffer from this. Therefore, we have laid a foundation that the future of digital design no longer excludes anyone and does not require people to adapt to their devices, but the other way around. The Thesis "Beyond Visual Design" focuses on inclusive design through multimodal interaction and adaptation.

Not only blind individuals are affected by visual impairments. Every person encounters situations where they have visual limitations. For instance, while driving, one may not be able to look at the car's touchscreen for safety reasons, or when taking care of young children, visual attention may be required elsewhere. Therefore, everyone benefits from inclusive design that engages multiple senses.
That's why we created a new design standard that serves as a foundation for full-fledged inclusivity, breaking the paradigm of visual-only design and expanding interaction.


The guide "Beyond Visual Standard", is aimed at everyone involved in design processes. It includes 10 overarching guiding principles that provide a solid foundation for inclusive design. Furthermore, 21 design principles describe the most important factors for inclusive digital interactions for blind and visually impaired people. They are divided into the categories: Perceptibility, Comprehensibility, Operability, and Adaptation.

To simplify integration into corporate processes, the guidelines are also available as a set of cards. These can be used in workshops, meetings and brainstorming sessions.


Case Study:

Digital Home Appliance Products


For the development, evaluation and presentation of the guidelines, a case study was designed based on three products. For this purpose, products were deliberately chosen that are essential for an independent lifestyle: Digital household appliances. Household appliances could be operated by blind people in the past, whereas digitalization, e.g. through touchscreen user interfaces, largely ensures that they can no longer be used.

The three products shown each have a different focus in the application of the guidelines. This shows that the "Beyond Visual Standard" can be used in a variety of ways for different use cases.

01 HAPTICSTOVE – Safely tangible.


The "HapticStove" induction cooktop is an inclusive cooktop that, through its functionality, interaction and design, guarantees people with severe visual impairments the same ease of use as people with full vision. The name "HapticStove" describes the most important feature of the cooktop: its haptic tangibility and operability. Despite digital functionality, the operation of the product does not require a graphical user interface.

Haptic Controls

Tangible Information

The smart haptic controls are clearly assigned to the heat sources and have haptic feedback for the setting. The controls use smart pot recognition to automatically tell you where a container is placed. In addition, the heat indicators let you feel on a tactile level where there is still residual heat.

Safe Exploration

Safe Exploration

The hazardous areas where heat occurs are palpable and securely delineated. This allows even individuals with complete blindness to safely approach them using their hands for orientation.

02 MULTISENSECOFFEE – Extensively multimodal


MultisenseCoffee" enables people with visual impairments to fully utilize the functionality of a modern coffee machine despite their limitations. The interaction with the product is evenly distributed across the senses of sight, hearing, and touch. This multimodality supports easy and intuitive operation for any individual with a sensory impairment. "MultisenseCoffee" allows for advanced settings to accommodate users' individual preferences and enables the ability to save them.

Multisensory Interaction

Multimodal Interaction

The haptic user interface panel and the output of information through auditory, tactile, and visual cues ensure optimal compensation for sensory impairments. Settings and system status are both visible and palpable, and error messages such as "low water level" are conveyed through three sensory channels.


MemoryPucks – Physical Shortcuts

"MultisenseCoffee" not only allows for adjusting settings according to individual preferences but also enables the saving of favorites. To make this process as simple as possible, six "MemoryPucks" are available. These "MemoryPucks" are visually contrasting due to their color scheme and tactually distinguishable due to their unique shapes. By simply placing a "MemoryPuck", favorites can be saved and easily accessed. The "MemoryPucks" thus serve as physical shortcuts.

03 ADAPTIVEOVEN: Individually adaptable.


"AdaptiveOven" is a highly functional oven that is capable of adapting to individuals with different abilities. The convertible graphical display, combined with auditory feedback and the central haptic control element, enables multimodal operation and dynamic adaptability of interaction with the device. This way, individuals with full visual ability, as well as blind and visually impaired individuals, can interact with the product equally, albeit in differently adapted ways.

Adaptive UI

Adaptive UI

"AdaptiveOven" can adapt its basic interaction mode to individuals with blindness or severe visual impairments through a pre-programmed mode. This mode affects both the visual representation of the interface and the weighting of sensory cues.
In the "StandardMode" (left), the user interface is heavily visually oriented, providing users with a detailed overview of all
functions with high informational content. In the "AssistedMode" (right), the visual representation of information is reduced to the essential elements. Selected functions are displayed in isolation, with increased font size, contrast, and visual clarity. Auditory feedback is provided through the voice assistant.

Linear Usability

Linear Process

For easy and intuitive operation, all fundamental functions of the oven can be controlled linearly through the haptic control element. The adjustable parameters can be easily changed by sliding the rotary dial further.

Dynamic Haptics

Dynamic Haptics

The rotary dial features dynamic haptic feedback. Depending on the variation in settings, it adjusts the fineness of the feelable grid and the resistance dynamically. As a result, different settings are perceived and differentiated through distinct tactile sensations.


Situational Adaption: ProactiveSense

The "ProactiveSense" feature can recognize the user's situation and adjust the display of information based on whether the user is in front of the device, away from it, or not in the room at all. This way, accessibility features originally designed for blind individuals can provide benefits for everyone, regardless of their visual ability.

Prototyping & Evaluation

During the process of the master's thesis, the developed guidelines were tested, evaluated, and revised through multiple low and mid fidelity prototypes in collaboration with individuals with visual impairments. This process allowed for the creation of a well-founded and functional theoretical framework for a better and more inclusive future of design.

Universal Benefit

The guidelines not only bring improvement for people with visual impairments but for all of us. The following examples demonstrate how multimodal design can benefit us in mastering different situational challenges. The AdaptiveOven, with its proactive adaptability, has the potential to adjust to various life situations. In automobiles, features like physical shortcuts (such as "MemoryPucks") can contribute to simplifying the operation of the infotainment system and keeping our focus on the road. Multisensory design is also advantageous in education. Learning processes that engage the whole body are significantly better remembered and internalized compared to solely reading a visual text.

Scenarios – AdaptiveOven, Automotive, Educational

BEYOND VISUAL DESIGN – Products Case Study