An apparatus for ophthalmic laser surgery comprises a source (28) for a pulsed femtosecond laser beam, a telescope (32) expanding the laser beam, a scanner (36) downstream of the telescope, for deflecting the laser beam in a plane perpendicular to the beam path, and also an f-theta objective (44) downstream of the scanner, for focusing the laser beam. In accordance with the invention, an entrance lens (52) of the telescope (32) takes the form of a controllable lens of variable refractive power. The entrance lens (52) is preferentially constituted by an electrically controllable liquid lens or liquid-crystal lens.