A coupling device for detachably connecting an eyepiece of an endoscope optical system with a camera lens exhibits a receptacle for the eyepiece, attachment means for securing the eyepiece in the receptacle, and a manually activated handle arranged on the outside for releasing the attachment. The attachment means are here controlled by the eyepiece in such a way as to automatically attach the eyepiece in the receptacle while introducing the eyepiece into the receptacle.
