A lens power measuring system has a light source and a fiber-optic light delivery system optically coupled to the light source to receive illumination light from the light source. The fiber-optic light delivery system has a transmit/receive end. The lens power measurement system also has a microscope objective optically coupled to the fiber-optic light delivery system through the transmit/receive end of the fiber-optic light delivery system, a movable mirror arranged to intercept at least a portion of light after having passed through the microscope objective, and an optical detection system optically coupled to the fiber-optic light delivery system to receive light after having been reflected from said movable mirror. The optical detection system is constructed to be able to determine a substantially maximum signal of light reflected from the movable mirror in correspondence with a relative position of the movable mirror to a lens to be measured. Methods of measurement include methods using such a lens system.