Abstract: A dual, stereoviewing operating microscope including a single objective lens adapted to provide a collimated beam of light which is intercepted and transversely redirected by a pair of reflecting prisms into two oppositely directed stereoscopic optical paths. Each stereoscopic optical path is provided with a pair of viewing eyepieces each of which has a zoom lens assembly. Each pair of eyepieces is independently operable of the other. The microscope also includes an aperture between the redirecting prisms intercepting the light from the objective lens in order to provide, through this aperture, a direct optical path between the objective lens and a camera or other recording device. A separate zoom lens assembly is inserted in this latter optical path and a mechanism is provided by which all zoom assemblies are simultaneously operable.