{"@context":{"dc":"http:\/\/purl.org\/dc\/elements\/1.1\/","skos":"http:\/\/www.w3.org\/2004\/02\/skos\/core#","skos:broader":{"@type":"@id"},"skos:inScheme":{"@type":"@id"},"skos:related":{"@type":"@id"},"skos:narrower":{"@type":"@id"},"skos:hasTopConcept":{"@type":"@id"},"skos:topConceptOf":{"@type":"@id"}},"@id":"https:\/\/digilab.ptb.de\/oiml-g-18\/vocab\/skos\/2038","@type":"skos:Concept","skos:prefLabel":{"@language":"en-EN","@value=":"vertex power           #01130"},"skos:inScheme":"https:\/\/digilab.ptb.de\/oiml-g-18\/vocab\/","dct:created":"2022-12-19 09:13:41","dct:modified":"2022-12-19 13:55:38","skos:scopeNote":[{"@lang":"en-EN","@value":"(1) The unit for expressing vertex power is the reciprocal metre (m-1). The name for this unit is the \u201cdioptre\u201d, for which the symbol is D.(2) Conventionally the back vertex power, in dioptres, is specified as the \u201cpower\u201d of a spectacle lens, although the front vertex power is required for certain purposes (for example in the measurement of some multifocal lenses). "}],"skos:definition":[{"@lang":"en-EN","@value":"there are two vertex powers of a lens, described in 3.7.1 and 3.7.2 "}],"skos:broader":["https:\/\/digilab.ptb.de\/oiml-g-18\/vocab\/skos\/2"]}