A sterile adapter for arrangement between a sterilizable endoscope and a camera head with a distal end attachable to the endoscope, and a proximal end attachable to the camera head, wherein the sterile adapter has a tube with a longitudinal axis, with a longitudinal portion having an internal diameter reduced in a plane perpendicular to the longitudinal axis and which forms a central opening which is dimensioned such that, while a free propagation of light is possible between the endoscope and the camera head along the longitudinal axis, it is nonetheless made difficult to reach through an interior of the sterile adapter enclosed by the tube.
