Per the news yesterday, in where Apple appears to have acquired LuxVue Technology, a stealth startup developing technologies centered around micro-LED displays:
LuxVue appears to be focused on very small displays, perhaps the kind that might find their way into an iWatch down the road. There, low power consumption could be especially critical. Anything that will allow a user to lengthen the time being recharges would likely make the iWatch more popular. Among the shortcomings of the first Samsung Galaxy Gear smartwatch was lousy battery life.
We're getting to the point of diminishing returns on screen resolution, but not so much with power consumption. Right now folks seem to begrudgingly accept that something as powerful and multifunctional as the iPhone probably can't and won't go a full day without charging, but a watch brings different expectations, and different requirements; chiefly nobody is used to charging a watch, ever, and a watch, at least at its most rudimentary level and unlike the iPhone, is always on.