Provided here are microscope objectives that include a first plurality of lenses positioned within the passageway on a sample end of the microscope objective and a second plurality of lenses positioned within the passageway and spaced apart from the first plurality of lenses and opposite the sample end such that the first plurality of lenses and the second plurality of lenses are aligned along an imaging axis and such that each individual lens is rotationally symmetrical about the imaging axis. Also included is a motor configured to move a carrier along the imaging axis to change a distance between each lens of first plurality of lenses relative to at least one lens of the second plurality of lenses.