But scientists have figured out how to make tiny wearable screens--with diagonals of less than half an inch. These devices permit the wearer to see everything around them. "People have been talking about this kind of thing for ten years," says John Fan, chief executive of Kopin, which makes these tiny displays. "But now the technology is here and it has the right price point." Westwood, one of Kopin customers, which sells small screens that surgeons can clip onto their glasses so they can glance at a patient's vital signs without having to lift their heads. These screens, often referred to as "heads up" displays, are used extensively by the military, which is loading soldiers up with displays that help them do everything from seeing around corners to referencing global positioning maps. "In the future, electronic eyewear will have to be like sunglasses, which perform a function but also look cool," says MicroOptical Marketing Vice President Mark Basler.