Abstract: Embodiments of the present invention provide method and apparatus for use during a neurosurgical procedure to enable a multi-coordinate manipulator ("MCM") to locate blood vessels and nerves in a patient's brain with submillimeter resolution. In addition, embodiments of the present invention provide method and apparatus for mapping oxygenation of brain tissue in three dimensions to differentiate tumor tissue from normal brain tissue with submillimeter resolution.

Abstract: A microscope for examinations and surgical operations on the eye, having provision for projecting onto the eye a hollow beam of illuminating light, the beam having a dark center portion of the same diameter as the pupil of the eye. Thus the surgeon may have adequate illumination of the external surface of the eye around the pupil, without projecting light which might be disturbing or damaging to the patient, onto the retina or fundus of the eye. The light blocking structure, in the form of an annular diaphragm with a light-impervious central portion, is located in the illuminating light beam at a point which is conjugated with respect to the object plane, i.e., the plane of the pupil of the eye being examined. The diaphragm may be moved aside to an ineffective position when required.