Abstract: A vision aid in the form of telescopic spectacles has two lens systems, which each comprise at least one objective lens (70) and one eyepiece (71). An autofocussing element which changes the focal length of the lens systems for sharp focussing thereof according to the distance of the telescopic spectacle from the object is assigned to the lens systems. Furthermore, an element for changing the magnification factor by changing the focal length of the lens systems (“zoom”) and finally an element for matching the parallax between the lens systems of the vision aid to the focal length which has been set according to the distance of the telescopic spectacles from the object are assigned to the lens systems. The parallax is adapted using adjustable optical elements (11) which are located in the beam path of the lens systems, with which elements the angle (13) between the beam paths (14) running from the lens systems (1) to the object can be changed.

Abstract: Wing parts (20, 21) which influence the lift of aircraft wings (1), especially wings (1) with a cross section and an angle of attack which is suitable for high-speed flight, which parts can be moved out of an aerodynamically inactive servicing position within the aircraft fuselage (30) or out of chambers (40) mounted on the wings (1) into an aerodynamically efficient active position and from the active position back into the servicing position, are assigned to the wings (1). These wing parts (20, 21) in their active position are located on the top (3) and optionally also on the bottom (4) of the wings (1) and are shaped for example such that the wing parts (21) located in their active position on the bottom (4) of the wings (1) jointly with the wing parts (20) located in their active position on the top (3) of the wings (1) increase the lift and optionally at the same time change the angle of attack of the wing.

Abstract: Magnifying spectacles for surgical use have an automatic focusing device, a device for automatically altering the magnification factor and a device for automatic parallax compensation corresponding to the current focal length. During surgical operations, alteration of the working distance is commonly necessary due to the positions of different operating sites. Automatic adaptation of the focal length and the parallax angle allows optimum optical configuration to be reached without the need for the surgeon to use his hands. Focusing can be adjusted using a foot switch.