The device (1) has an optical transmission system (5) for transmitting femto-second pulses (L) to different projection lenses (3) of a lens change device (4) for projecting the femto-second pulses into an eye tissue (21). The lens change device is designed for replacing and attaching the projection lenses to the optical projection system. The projections lenses are mechanically connected with each other and the lens change device is designed to supply one of the projection lenses for attaching to the optical transmission system.