Non-visual access to mobile devices: A survey of touchscreen accessibility for users who are visually impaired

Accessibility revolves around building products, including electronic devices and digital content, so that diverse users can conveniently utilize them, irrespective of their capabilities. In recent years, the concept of touchscreen accessibility has gained a remarkable attention, especially within the considerable reliance on mobile touchscreen devices (MTDs) for information acquisition and dissemination as we witness nowadays. For users who are visually impaired, MTDs unlock different opportunities for independence and functioning. Thus, with the increasing ubiquity of MTDs and their potential extensive utility for all demographics, it becomes paramount to ensure that these devices and the content delivered on them are accessible. And while it might seem straightforward to achieve accessibility on MTDs, attaining this outcome is governed by an interplay between different elements. These involve platform (i.e., operating system) built-in support of accessibility features, content rendering modalities and structures pertaining to user needs and the peculiarities of MTDs as informed in standard accessibility guidelines, user studies uncovering preferences and best practices while interacting with MTDs, national legislations and policies, and the use of third-party devices such as assistive technologies. In this paper, mobile touchscreen accessibility for users who are visually impaired is surveyed with focus on three aspects: (1) the existing built-in accessibility features within popular mobile platforms; (2) the nature of non-visual interaction and how users who are visually impaired access, navigate, and create content on MTDs; and (3) the studies that tackled different issues pertaining to touchscreen accessibility, such as extraction of user needs and interaction preferences, identification of most critical accessibility problems encountered on MTDs, integrating mobile accessibility in standard accessibility guidelines, and investigation of existing guidelines in terms of sufficiency and appropriateness.