Building Accessible Reading Apps: Supporting Visually Impaired Users

In an increasingly digital world, ensuring that content is accessible to everyone is not just a matter of compliance, but a fundamental commitment to inclusivity. For publishers, this means delivering digital books and other content in a way that caters to users with diverse needs, particularly those who are visually impaired. Building an accessible reading app requires careful consideration of design, technology, and content standards.

Accessibility for visually impaired users in a reading app primarily revolves around two key areas: the app's user interface and the content itself. Both must be designed to work seamlessly with assistive technologies and offer customisation options that enhance readability.

Understanding Accessibility Standards: WCAG and EPUB 3

The foundation of any accessible digital product lies in adhering to established standards. For reading apps, the primary benchmark is the Web Content Accessibility Guidelines (WCAG). While originally developed for web content, WCAG principles are widely applicable to native applications and provide a robust framework for ensuring usability for people with disabilities. Key WCAG principles include perceivability, operability, understandability, and robustness.

Beyond the app interface, the content itself must also be accessible. This is where the EPUB standard, particularly EPUB 3, plays a crucial role. EPUB 3 was designed with accessibility at its core, offering features that are vital for visually impaired readers. These include:

• Semantic Markup: Proper use of HTML5 elements (e.g., <nav>, <aside>, <figure>) provides structure that screen readers can interpret, allowing users to navigate content logically.

• Text-to-Speech (TTS) Support: EPUB 3's robust text model facilitates high-quality text-to-speech rendering, which is essential for users who rely on auditory presentation of content.

• Image Descriptions: The ability to embed alternative text (alt attributes) for images ensures that visual content is described to visually impaired users. Long descriptions can also be linked for more complex graphics.

• Customisable Presentation: EPUB 3 allows reading systems to override publisher styling, enabling users to adjust font size, line spacing, colours, and contrast to suit their individual needs.

• Media Overlays: For a more integrated experience, EPUB 3 supports synchronised audio and text, allowing users to follow along with professional narration.

Eden Interactive's Publish360 platform is built upon these principles, leveraging Readium, an open-source rendering engine that inherently supports EPUB 3. This ensures that the underlying technology is capable of delivering accessible content from the outset. Publishers can learn more about EPUB 3 accessibility and its importance.

Designing for Screen Reader Compatibility

For many visually impaired users, screen readers are their primary interface with digital content. A truly accessible reading app must be designed to work seamlessly with these assistive technologies. This involves several critical considerations:

• Logical Navigation: Screen readers navigate user interfaces sequentially. Ensure that interactive elements are presented in a logical order that makes sense when read aloud. Users should be able to move through menus, buttons, and content sections predictably.

• Descriptive Labels and Roles: Every interactive element (buttons, links, input fields) should have a clear, descriptive label that a screen reader can announce. Avoid generic labels like