Do you need iPhone, if iWatch has the same, or bigger display? (curved sapphire glass). Smartphone solves problem of having a computing device all the time with you, but in order to get that you have to pay with screen size. Smartglasses solves the same problem as smartphone, but without tradeoffs. They can display touch, augmented, or desktop, or tv interfaces. You don't need a tablet, phone, laptop, desktop, tv. You need boxes with small(pocket), medium(backpack), and large(desk) computing power, and glasses that can receive video over the air. (and some input method). If glasses are only for display, they don't need large battery.