[GHFigs]

The inevitability of miniaturization notwithstanding, it's slightly challenging to imagine a less obtrusive version of something whose defining property is that it sits on your face.

Maybe in five years we'll all be wearing smart-monocles. Who knows?

[manaskarekar]

How about:

1. Circuit-printed contact lenses.

2. Soluble eye-drop based displays that spread out over the eyes.

3. The much much harder brain implants/nanobot injections that respond to your impulses etc?

I'm sure back in the 40s/50s smartphones and tablets probably would have seemed pretty out there too.

[wonderzombie]

I (and a great many other humans) already wear an accessory which sits on the face. :)

When spectacles were first invented, they may well have been obtrusive and required some social adjustment. Now they're thoroughly assimulated. They are unobtrusive, and one's choice of frames/style often serves as a fashion statement.

[GHFigs]

I wear glasses, too, but I think of it as a bug when there's something on the lens or when I talk to them. It feels like the very unobtrusiveness that makes them useful.

Maybe it's Google's habit of showing off Glass without lenses that makes me think of it as 'as screen on your face' rather than 'fancy glasses'. It reads as 'Bluetooth earpiece' more than 'hearing aid'.

Also, I kind of just want a monocle.

[TeMPOraL]

And in ten years smart contact-lenses. It's not hard at all to imagine.

[tjmc]

Not hard to imagine but very hard to do. There are several huge challenges:

- Power. Contact lenses are too small to hold batteries that will last for a reasonable period of time. You could possibly use inductive coils in conjunction with regular eyewear but that means a fair electromagnetic field aimed right at your eyes and some obvious health risks.

- Optics. This is actually 2 issues - First, you can't focus on anything that's literally right on your eye so you'd need to do something very clever here. Possibly direct laser projection from the lens to the retina. Second, all the electronics in the lens will be opaque and could occlude your regular vision. Let's suppose you can move most of it to the outside of the lens (as with coloured contacts now), the HUD part is still going to cover part of your pupil. So it needs to be really tiny and still produce a clear image. Not impossible maybe but very hard.

- Health. Less of a showstopper, but contact lenses need to breathe. Impeding the flow of oxygen to the surface of the eye can lead to corneal neovascularization - the growth of blood vessels over the cornea. So ideally these contact lenses need to be gas permeable as well.

[TeMPOraL]

Very hard they are. But that's what we have engineers for :).

See what you just did: you outlined some real challenges we face if we want to improve this technology. And now we have something that is in domain of science and engineering, so we can discuss ideas and solutions. We're in a much better state than if we just left it on "it's hard to imagine" or "it's impossible".