{"@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\/105","@type":"skos:Concept","skos:prefLabel":{"@language":"en-EN","@value=":"astigmatic power lens           #01135"},"skos:inScheme":"https:\/\/digilab.ptb.de\/oiml-g-18\/vocab\/","dct:created":"2022-12-19 09:13:28","skos:scopeNote":[{"@lang":"en-EN","@value":"One of these powers may be zero, with the corresponding focal line at infinity. Lenses referred to as toric lenses, sphero-cylindrical lenses and cylinder lenses are all astigmatic. "}],"skos:definition":[{"@lang":"en-EN","@value":"lens bringing a paraxial pencil of parallel rays to two separate line foci mutually at right angles and hence, unlike a spherical lens, having two principal powers "}],"skos:broader":["https:\/\/digilab.ptb.de\/oiml-g-18\/vocab\/skos\/2"]}