A device and a method for fixing a relative geometric position of an eye with respect to an ophthalmological diagnosis and/or therapy system. A device having a container with upper edge designed to produce a mechanically fixed connection between the container and the ophthalmological diagnosis and/or therapy system, and a lower edge which can be placed with a form fit onto the eye, and a clamping mechanism for producing a force-fit connection of the container to the eye, wherein the clamping mechanism has a movable connection to the container is a fixed rotation point or a fixed rotation axis in a jacket area of the container, and by a corresponding method.
