1. A microscope-integrated intraoperative optical coherence tomography (OCT) scanner system having automated tracking of an instrument tip, the system comprising: at least one scanning mirror configured such that a field of view of the OCT scanner system is determined by at least one of a position and an orientation of the at least one scanning mirror; a drive system configured to control the at least one of the position and the orientation of the at least one scanning mirror; a plurality of camera assemblies configured to determine respective two-dimensional projections of the positions of a plurality of markers attached to a surgical instrument; a stereo vision system configured to determine a three-dimensional location of each of the plurality of markers from the determined two-dimensional positions at the plurality of camera assemblies; an instrument tracking component configured to determine a position of a working tip of the surgical instrument according to the determined three-dimensional locations of the plurality of markers; and a drive control configured to instruct the drive system to adjust the at least one of the position and the orientation of the at least one scanner mirror such that the field of view of the OCT scanner system is determined from a position of the working tip of the surgical instrument; wherein the stereo vision system is configured to calculate a first ray from an origin of a first camera of the plurality of camera assemblies to a given one of the plurality of markers, calculate a second ray from a center point of a second camera of the plurality of camera assemblies to the given one of the plurality of markers, find a shortest line segment connecting the first ray and the second ray, and determining the three-dimensional location of the given one of the plurality of markers as a midpoint of the shortest line segment connecting the first ray and the second ray.