An optical module for increasing magnification of a microscope includes an objective and an eyepiece between which is an optical path for light to travel. The optical includes light diverging elements for dividing the optical path into two parallel light paths after leaving the objective; and several orthonormally-arranged reflective elements including at least a first and a last reflective element, each reflective element having a reflective surface diagonal relative to the orthonormal arrangement of the elements, and also arranged to successively reflect the parallel light paths, from element to element, from the objective when the module is inserted in the optical microscope, beneath the eyepiece. Also included are light converging elements for converging the parallel paths into a single path before producing an image at the eyepiece.