Abstract: Organs of the eye which are situated in the region of the anterior chamber of the eye are protected during eye lens surgery by a device in which a surgical instrument, such as a tip of a phacoprobe, is guided to the posterior chamber of the eye through a tunnel placed in the cornea/sclera region into the anterior chamber. In order to particularly protect the iris of the eye, a push-in part is provided and can be pushed through the tunnel into the anterior chamber at a push-in length which covers the iris at least partially in the radial direction. The push-in part is connected with a holding part which can be supported outside the tunnel on the exterior surface of the eye. An area which extends in the tunnel and is used for thermal control has a smaller width than an area which projects into the anterior chamber.