The invention proposes a manual measuring appliance (112) and an analytical measuring system (110) which can be used to measure at least one analyte in an eye fluid of an eye (114). The handheld measuring appliance (112) comprises a measuring system (120) and a positioning system (122). The measuring system (120) can measure at least one property of the at least one analyte and/or at least one analyte-dependent change of property of at least one ocular sensor (116) in the eye fluid, and this can be used to infer a concentration of the analyte in the eye fluid. The positioning system (122) is set up to measure a spatial positioning, wherein the spatial positioning comprises a distance between at least one measurement location in the eye (114) and the handheld measuring appliance (112) and also furthermore at least one further positioning co-ordinate. The positioning system (122) comprises at least one of the following systems: a camera system, particularly a monocular or binocular camera system, having at least one camera (410; 910); an image recognition system; a triangulation system; a propagation time measuring system, particularly for 1-, 2- or 3-dimensional propagation time measurement, particularly using at least one laser and/or at least one phase mix detector (PMD); a 1-, 2- or 3-dimensional intensity measuring system for at least one signal; a 2- or 3-dimensional magnetoresistive measuring system.