A guide roller projects from the side surface of an optical system body. The optical system body is held to be elevatable within a predetermined range along an arcuate guide member. A weight balancing means incorporating a spring attaches to the lower corner on the side surface of the optical system body. A hook attaches to one end of the arcuate guide member. A pulley attaches to the upper end of the arcuate guide member. One end of a wire fixes to the hook. The spring of the gravity balancing ...

An instrument stand for supporting ophthalmological instruments. The instrument stand may include a console housing configured to receive differently-configured electronics modules. In addition to, or instead of, the interchangeable electronics modules, the console housing may also be provided with a removable shelf that is resistant to unintentional removal during use. In addition to, or instead of, the interchangeable electronics modules and removable shelf, the instrument stand may also inclu...

A novel vision tester and vision testing method is described which comprises a pair of translucent displays, each transilluminated by electroluminescent lighting panels, the images of the two patterns being superimposed to provide a combined image characterized by a pattern of variable contrast. Light sensors near each light panel provide a measure of the relative intensities of the two images, which provides a measure of the contrast of each combined image. Contrast may be directly read out by ...

A process for the simultaneous removal of sulfur oxides and nitrogen oxides from power plant stack gases comprising contacting the stack gases with a supported iron oxide catalyst/absorbent in the presence of sufficient reducing agent selected from the group consisting of carbon monoxide, hydrogen, and mixtures thereof, to provide a net reducing atmosphere in the SO.sub.x /NO.sub.x removal zone. The sulfur oxides are removed by absorption substantially as iron sulfide, and nitrogen oxides are re...

A lightweight, pocket-sized, hand-held near vision test apparatus that selectively retroilluminates different near vision test objects located on an interchangeable near vision test card, or alternatively, selectively displays near vision test objects on a flat panel display screen. The apparatus allows the examiner to electronically direct the patient's attention to selected near vision test objects, while providing a baseline amount of contrast illumination.

A process for optimizing the removal of nitrogen oxide (NO.sub.x) and sulfur oxide (SO.sub.X) from flue gases is provided in which the flue gases pass over a lanthanide-oxygen-sulfur catalyst. The catalyst has active sites provided on its surface which promote the dissociation of NO.sub.X and receive and entrap oxygen released during the dissociation of the NO.sub.X. While the flue gases pass over the catalyst, a reducing gas contacts the catalyst to reduce the oxygen on the active sites of the ...

The invention relates to a target-detection and target-alignment device for a missile system whose field of view is expanded by a wide-angle lens system, which does not contain any optical components which must be additionally moved, and which is equipped with an integrated system for correction of homogeneity of the ambient conditions. Two radiometers or photometers are connected to two emission surfaces positioned on opposite sides of the image of the field of view to adjust the angle of the t...

Catalysts for conversion of nitrogen oxides comprises a porous ceramic carrier, and 0.1 to 10% by weight of copper oxide in terms of copper metal, 0.1 to 20% by weight of lanthanum oxide in terms of lanthanum metal and 0.01 to 12% by weight of zirconium oxide in terms of zirconium metal, based on the weight of the carrier, these oxides being supported on the carrier. The catalysts are brought in contact with a gas containing nitrogen oxides in the presence of ammonia and sulfur oxides, thereby d...

A method for evaluating and measuring accommodation amplitude in one or both eyes of a person by subjecting the person to a near-vision visual acuity test comprising a target having optotypes displayed thereon, different targets having different sized optotypes, determining the nearest point at which the person accurately identifies a majority of the optotypes on the target, and introducing either a sufficiently powered plus lens or sufficiently powered minus lens to locate the nearest point wit...

A method and device for optically stimulating the visual system during static perimetry and for objectively evaluating adequate stimulus-related electrophysiological and/or magnetophysiological quantities. Light stimuli with defined parameters derived from a predetermined correlation function and from the known intensity dependence of the excitation response amplitude are presented to the observer. The excitation responses contained in the ERG and/or in the EEG/MEG are detected and processed. Th...