  Augmented Reality (AR) technology creates new immersive experiences in
entertainment, games, education, retail, and social media. AR content is often
primarily visual and it is challenging to enable access to it non-visually due
to the mix of virtual and real-world content. In this paper, we identify common
constituent tasks in AR by analyzing existing mobile AR applications for iOS,
and characterize the design space of tasks that require accessible
alternatives. For each of the major task categories, we create prototype
accessible alternatives that we evaluate in a study with 10 blind participants
to explore their perceptions of accessible AR. Our study demonstrates that
these prototypes make AR possible to use for blind users and reveals a number
of insights to move forward. We believe our work sets forth not only exemplars
for developers to create accessible AR applications, but also a roadmap for
future research to make AR comprehensively accessible.
