An ophthalmic surgical microscope can include a movable optical element positioned in an optical pathway of light reflected from a surgical field. The movable optical element can be configured to oscillate in a direction along the optical pathway. The microscope can include an actuator coupled to the movable optical element and configured to move in response to a control signal. The microscope can include a computing device in communication with the actuator and configured to generate the control signal to move the movable optical element. In some embodiments, the computing device is configured to generate the control signal to move the movable optical element with an oscillation frequency greater than the critical flicker fusion rate.
