A microscope includes at least one correction unit arranged in a beam path for correcting a variable spherical aberration. The correction unit has at least one optical correction element that is arranged in a convergent or divergent area of the beam path such that the optical correction element is movable along an optical axis. The at least one optical correction element has at least one correction surface. A part of the at least one correction surface through which the convergent or divergent area of the beam path passes forms a correction-effective surface section whose radial extension crosswise to the optical axis is adjustable by moving the correction element along the optical axis.