A system and an apparatus for connecting a fiber optic or rigid light guide to a light source are provided. The fiber optic or rigid light guide has one end connected to a ferrule with a contact surface. The system includes a connecting element connectable to the light source, into which the ferrule can be inserted. The connecting element has a number of radially movable fastening portions, wherein the fixing portions are radially biased and cooperate with the contact surface, when the ferrule is inserted into the connecting element, whereby a first retention force is applied to the contact surface, and a fixing element is positioned in such a way that it cooperates with the fastening portions so that a second retention force, which is greater than the first retention force, is applied to the contact surface.