Microscope with extended field of vision

An optical system is provided for creating a mosaic image of a large field of view through a microscope at fast refresh rates of about 25 Hz with a high resolution that is free of blurring or aberrations. The optical system includes an objective lens assembly ( 20 ), an iris ( 30 ), one or more scanning mirrors ( 40 ) for high-speed scanning, one or more imaging lenses and irises ( 50, 60, 80 ), and a high-speed imaging device ( 70 ) arranged in that order from an object. The optical system also includes a mechanism for processing and constructing scanned and captured images into a mosaic image.