VR and AR glasses are gaining popularity, and so are TVs and Monitors you can use from a couch or bed... and the current idea of using two different things, one being huge and needing 2 hands and both needing a desk, to type and navigate, is just silly.
A gadget with a trackball at your thumbtip,
and selection of buttons for all 5 fingers on one hand, which you hold in your "fist" (or is connected to your hand with a strap or ring), and optional Inertial-sensors makes *considerably* more sense.
You'd enter text with combinations of buttons being pressed (so no need for 100+ actual buttons), and navigate (and scroll and arrow) with the trackball (along with holding modifier keys with a spare finger to indicate what kind of movement and cursor (mouse or keyboard) to effect) etc etc.
My rough calcs are...
Keyboards have 33 symbols other than numbers and letters
!@#$%^&* ()_+-=~` {}|[]\: ";'<>?,./ [and space = 33 symbols],
There's at least 6 "modifier" keys already shift, ctrl, alt, win (r.shift, r.ctrl) aka command/option on mac - add another 7th one to turn numbers etc into F1..F12
esc tab up down left right PgUp PgDn Home End Ins Del Backspace enter = 14 extra movement etc keys
capslock, PrtSc, ScrlLk, Pause, mouseclick left/middle/right, mousemove vert-scroll horiz-scroll, fwd, back buttons
so all-in-all: a user would have to learn 76 "moves" (combination of finger presses on unique buttons) to cover the entire possible gamut of all QWERTY keyboard inputs and all mouse movements and clicks to use this system.
Learning: 48 symbols, + 7 modifiers, + 18 extra + 3 mouse = 76 key combos.
That sounds highly doable.
Other benefits - every finger has only a small number of keys, none of which are shared with other fingers - so never need to look for anything (perfect for VR/AR/lying-down/etc).
Being able to move the typing cursor by emulating arrow keys via a modifier-key and trackball would be vastly faster and more intuitive than real actual keys (although for compatibility and gaming etc - arrow inputs via buttons would still be supported too)
Using only one half of your brain for text input it almost certainly going to have some very interesting mental effects - hopefully good. Left and Right brain are supposedly implicated in different things (logic/art/etc), so deliberately picking which hand to use for input should have marked effect on someones personality/expertise
Good for disabled people, and for older people who are having coordination issues (and even middle-aged people... ever noticed how, as you get older, the kinds of mistakes that you make as you type get more-and-more linked to wrong timing between each of your input hands ???)
With a decent HUD - makes it safe to text and drive :-)