I've started to need reading glasses more and more over the past few years, and that's starting to be a real drag for some gadgets. It's frustrating because when I'm not sitting at my desk, walking around, my reading glasses make the world around me fuzzy, and I take them off -- which makes quickly accessing something like my phone, or a smaller smartwatch screen -- seem really challenging. But in theory, I love the idea.
I hear ya.
I'm far sighted, which means I can see normal things fine without glasses, even read. But my focus point is "out there" so small screens with small print are next to useless for me. My wife hands me her iphone to read a funny FB article, and it's too damn small and FB won't rotate or resize the content. So I just get frustrated and miss out.
tiny screens are not good for 50% of the population (assuming relatively even distribution across ages).
With touch interfaces, they're not so good for UI either as more people have fat stubby fingers than super thin pointing stick fingers.
I hate to be Debbie Downer on this, because as an idea it's great. But as I've gotten older, wiser, and considered more user interface concepts (remember, I'm an application developer, I do this for a living), it has problems that will turn off users once they actually use it.
Kinect has similar problems when folks thought it would open up Minority Report like user interfaces by waving your hands. The problem is exactly why touch screens have taken off. Touching a screen is VERY intuitive for a user interface. Your eye sees the object on the screen, and your muscles direct your hand to make contact and do a motion with perfect feedback (you feel the screen surface, you see the object react).
Holding your hand in the air to touch nothing (and with Kinect, literally nothing, the screen is another 4 feet away) is tiring and non-tactile. You never really know if your hand is in the right place because your hand isn't even touching a hologram to SEE that it's correct.
Again, we'll have to see how it turns out. As smartphones have evolved to some pretty large screens with users accepting that bulk (remember pre-iPhone when they were about to announce cell phones the size of chapstick tubes?). It turned out, the drive to make everything smaller, while valuable, transformed into enabling larger interfaces while the guts were very tiny and compact.
Thus, we may see a smart watch design that has the optimal screen size and minimal wrist band that will appeal to most folks so it doesn't look like a clunky computer strapped to your wrist.