The present invention is directed to an arrangement and method for positioning the device with respect to the patient's eye to be examined in x-, y- and/or z-coordinates. The ophthalmologic device comprises a controllable illumination unit, an observation system, an image recording unit, a central control unit, an output unit, an eye tracker unit, and means for relative positioning. The imaging system of the eye tracker unit has at least two different adjustable magnifications. In the method for positioning the ophthalmologic device, the signal of the eye tracker unit is used not only to track a measuring mark and/or grid structure projected on the eye but also to detect the position of the patient's eye with respect to the optical axis of the ophthalmologic device. The solution proposed with the ophthalmologic device according to the invention makes it possible to automatically position the entire device with respect to the eye to be examined. The examination and determination of the biometric data of an eye can be simplified and substantially accelerated in this way.