Today, the underlying theoretical and methodological foundations as well as implementations in the field of accessibility are largely based on plans, metrics and heuristics. There is an obvious tension between these norms and those of the overall spirit of the times, which leans heavily towards improvisations, diversity, and ever-changing affordances. The parallel evolution of human computer interaction (HCI) has been characterized as three waves, each building on the previous one, resulting in an in-depth understanding of the interwoven activity of humans and non-humans (artifacts). Now when facing the era of mixed reality, accessibility can gain considerably from HCI’s, usability’s and interaction design’s bodies of knowledge.