Dictation in some cases sure, but it's not really secure if you're around people, and could also get weird talking to air all the time. I think if ar/wearable screens really want to take off were going to need an entirely new input method. Typing on a virtual keyboard is just so impractical, especially if you're say on a train or something. I think it'll be something like what I described, a lightweight wearable glove or fingertip sensor or something, and you input based on fingertip taps. You can keep your hands down by your sides while typing, don't have to flail about in the air just to quickly google something or answer the text that popped up on your glasses. Or a physical little keypad that can slip in your pocket, but with few enough buttons that you can type without having to look at it, like t9 texting.