Fundamentals of Wearable Computers and Augmented Reality, 2nd Edition

28 Fundamentals of Wearable Computers and Augmented Reality

sound. If the user ignores the alert, nothing happens. However, if the user tilts his

head up, the screen lights show the text. The user can read and dismiss it with nudge

of his head upward. Alternatively, the user can say “OK Glass, reply” and dictate

a response. Because Glass displays a limited amount of text on the screen at once,

interactions are short or broken into multiple small interactions. Ideally, such on-the-

go interactions should be around four seconds or less (Oulasvirta etal. 2005) to help

keep the user focused in the physical world.

Glass is also designed to interfere as little as possible with the user’s senses. Not

only is the display mounted high enough that it ...