Just as cutting, welding and drilling are industrial applications, so are they medical applications. Lasers that enable machine tools also enable, in skilled hands, delicate surgical instruments. The laser's industrial roots took hold long before its surgical ones, just as crude spears and hammers appeared in history long before scalpels: Finesse is harder to develop. Now, however, the medical device industry is catching up, developing and refining surgical instruments for precision "machining" of human tissue. A key and booming application area, for example, is laser vision correction, in which physicians "machine" the cornea to produce a more ideal shape. This application demands extreme precision, as do the growing industrial applications in micromachining. As these precision applications grow, surgeons may find that they have skills in common with machinists who employ computer numerical controls to guide lasers through complex maneuvers.