Abstract: A microscope head includes a housing having a pivot axis located generally at a center of gravity of the housing. At least one handle is connected to the housing coaxially with the pivot axis. Mounting structure is for rotatably mounting a support arm coaxially with the pivot axis. A tension control ring is attached coaxially with the pivot axis for varying a rotation force required to rotate the housing with the handle about the pivot axis. A magnification selector mechanism is connected to the housing coaxially with the pivot axis.

Abstract: An objective lens assembly 316 to be attached to a surgical microscope includes an objective lens 328, a roll section 318, a pitch section 320, and an attachment mechanism 330. The roll section 318 allows the objective lens 328 to be rotated sideways without causing a pair of eyepieces 324 to move. The pitch section 320 allows the objective lens 328 to be rotated towards and away from the pair of eyepieces 324 without causing the pair of eyepieces to move. A surgical microscope 300 including the objective lens assembly 316 also includes a microscope body 308 and support structure 302, 304, 306, and 310.

Abstract: A drape for a surgical microscope comprising a flexible cover for separating the microscope from the surgical field. There is a frame in the cover adapted to be secured over the objective lens of the microscope, and a dome-shaped protective window in the frame. The window is oriented so that when the frame is secured over the objective lens the dome extends toward or away from the objective lens to minimize reflection of light from the protective window into the optical path of the microscope.

Abstract: A zonal beamsplitter for use with surgical microscopes including a pair of right triangular prisms positioned adjacent to each other in opposing relation along substantially planar surfaces defining their respective hypotenuses. The planar surface of one prism is bi-zonal and includes a first zone for diverting substantially all of a portion of an image-quality optical signal at an angle from the direction of travel of the optical signal, and a second zone for conducting substantially all of the remaining image-quality optical signal therethrough. The plane of the first zone may be offset from that of the second zone and/or coated with an opaque reflective surface such as a metal foil.