Abstract: An amplifying circuit comprises a differential input stage having a first input terminal, a second input terminal, and an intermediate node, wherein the differential input stage is configured to generate a differential current flowing through the intermediate node in response to an input voltage difference between the first and second input terminals. The amplifying circuit further comprises a first current source coupled to the intermediate node, which is configured to provide a first bias current which allows the differential current to vary within a predetermined range. The amplifying circuit further comprises an output terminal coupled to the intermediate node, and a second current source coupled to the intermediate node and configured to provide a second bias current. The second bias current compensates the differential current and the first bias current and produces an output current flowing through the output terminal in a predetermined direction. A measurement device is also described.

Abstract: An amplifying circuit comprises a differential input stage having a first input terminal, a second input terminal, and an intermediate node, wherein the differential input stage is configured to generate a differential current flowing through the intermediate node in response to an input voltage difference between the first and second input terminals. The amplifying circuit further comprises a first current source coupled to the intermediate node, which is configured to provide a first bias current which allows the differential current to vary within a predetermined range. The amplifying circuit further comprises an output terminal coupled to the intermediate node, and a second current source coupled to the intermediate node and configured to provide a second bias current. The second bias current compensates the differential current and the first bias current and produces an output current flowing through the output terminal in a predetermined direction. A measurement device is also described.

Abstract: To enable evaluation of the binocular performance of spectacle lenses and display of the result of the evaluation, a method and an apparatus for evaluating and indicating the binocular performance of spectacle lenses. Binocular performance indexes indicating the binocular performance of the spectacle lenses to an object point within a visual field when it is observed through specific positions on both lenses are defined. For all object points in the visual field, the binocular performance indexes are derived. An image of the visual field, in which each pixel is assigned a monochromatic luminosity or a set of primary RGB color luminosity according to the value of the binocular performance index for viewing the corresponding object point, is created and displayed.