Abstract: A compact and precise phoropter of low requirements as to material and favorable as to kinematics comprises two observation channels in each of which a plurality of equal sized disks are rotatably and coaxially arranged about an axle, each of said disks being provided with a number of element sites where spherical lenses, cylindrical lenses, cross cylinders and further optically effective accessory elements are located. At least the cylindrical lenses are seated for rotation on said disks and are provided with first drive wheels, the diameters of the latter being substantially equal to the diameter of a second drive wheel rotatable with the axle and being associated to the respective disk. The diameters of the entire disks are determined by the diameters of the first and the second drive wheels and are at least three-fold the diameter of the first drive wheels.

Abstract: A phoropter comprises two observation channels, in each of said observation channels a plurality of disk-shaped mounts, rotatably seated about at least one axis, for mounting optically effective members and drive means for rotating said mounts. The drive means are piezoelectric motors, each of which is, on the one hand, connected to a base and, on the other hand, provided with a driving end portion, preferably a driven member which executes a rotating motion. The driven member is, compared to the piezoelectric motor, of small design.

Abstract: The invention relates to a displacement system for ophthalmologic examination units constituted of an instrument base section and an accessory section for mounting three ophthalmologic devices, said accessory section being connected by two lever means to said base section to enable displacement of the former relative to the latter from a first end position via an intermediate position into a second end position in the latter two positions relative to the said first end position the accessory section is displaced in parallel and at right angles relative to the base section so that the accessory section projects past over the base section. In this manner the opthalmologic devices are brought into an operation position in front of a patient and operator. A further lever system in combination with the lever means pivots a head rest to a patient in the intermediate and second end position, which head rest remains unchanged even when the ophthalmologic devices are changed for operation.