Windows 8 touchscreen pain
Indeed, Apple's Steve Jobs – not usually one to dismiss a pretty gadget on the grounds of uselessness – once said he'd never launch a touchscreen laptop because of what he called "gorilla arm".
"We've done tons of user testing on this," he said back in 2010, "and it turns out it doesn't work. Touch surfaces don't want to be vertical. It gives great demo, but after a short period of time you start to fatigue, and after an extended period of time, your arm wants to fall off."
It is possible, of course, to position a laptop so that the screen is reachable without lifting the elbows from the desk; but this means bringing it much closer than most people find comfortable visually.
Microsoft's online advice on using a PC safely doesn't mention touchscreens at all – and, ironically, instructs users to avoid just those movements that a touchscreen notebook demands.
A company spokesperson said Microsoft had no advice for users about safe use of the Surface touchscreen, and no comment about possible health issues.”
“Although we reached out to Microsoft for this story, the company did not respond to our request to comment.
In order to touch the display on a notebook with that capability, users either have to fully extend their arm (bad and uncomfortable), lean forward (bad and awkward) or move the display closer (bad for your vision).”
In order to interact with a touch UI for longer periods of time, I think that you would need something like an eye tracker built into the tablet or notebook.
There are consumer-level eye trackers that are available now, and were demoed at CES.
Look at any interface widget to highlight it, and then touch the keyboard to activate and select it. It can basically turn a non-touch screen into a touchscreen.