ISO 8596-2009

REFERENCENUMBERISO85962009EISO2009INTERNATIONALSTANDARDISO8596SECONDEDITION20090701OPHTHALMICOPTICSVISUALACUITYTESTINGSTANDARDOPTOTYPEANDITSPRESENTATIONOPTIQUEOPHTALMIQUEESSAIDACUITVISUELLEOPTOTYPENORMALISETSAPRSENTATIONCOPYRIGHTINTERNATIONALORGANIZATIONFORSTANDARDIZATIONPROVIDEDBYIHSUNDERLICENSEWITHISONOTFORRESALENOREPRODUCTIONORNETWORKINGPERMITTEDWITHOUTLICENSEFROMIHS,ISO85962009EPDFDISCLAIMERTHISPDFFILEMAYCONTAINEMBEDDEDTYPEFACESINACCORDANCEWITHADOBESLICENSINGPOLICY,THISFILEMAYBEPRINTEDORVIEWEDBUTSHALLNOTBEEDITEDUNLESSTHETYPEFACESWHICHAREEMBEDDEDARELICENSEDTOANDINSTALLEDONTHECOMPUTERPERFORMINGTHEEDITINGINDOWNLOADINGTHISFILE,PARTIESACCEPTTHEREINTHERESPONSIBILITYOFNOTINFRINGINGADOBESLICENSINGPOLICYTHEISOCENTRALSECRETARIATACCEPTSNOLIABILITYINTHISAREAADOBEISATRADEMARKOFADOBESYSTEMSINCORPORATEDDETAILSOFTHESOFTWAREPRODUCTSUSEDTOCREATETHISPDFFILECANBEFOUNDINTHEGENERALINFORELATIVETOTHEFILETHEPDFCREATIONPARAMETERSWEREOPTIMIZEDFORPRINTINGEVERYCAREHASBEENTAKENTOENSURETHATTHEFILEISSUITABLEFORUSEBYISOMEMBERBODIESINTHEUNLIKELYEVENTTHATAPROBLEMRELATINGTOITISFOUND,PLEASEINFORMTHECENTRALSECRETARIATATTHEADDRESSGIVENBELOWCOPYRIGHTPROTECTEDDOCUMENTISO2009ALLRIGHTSRESERVEDUNLESSOTHERWISESPECIFIED,NOPARTOFTHISPUBLICATIONMAYBEREPRODUCEDORUTILIZEDINANYFORMORBYANYMEANS,ELECTRONICORMECHANICAL,INCLUDINGPHOTOCOPYINGANDMICROFILM,WITHOUTPERMISSIONINWRITINGFROMEITHERISOATTHEADDRESSBELOWORISOSMEMBERBODYINTHECOUNTRYOFTHEREQUESTERISOCOPYRIGHTOFFICECASEPOSTALE56CH1211GENEVA20TEL41227490111FAX41227490947EMAILCOPYRIGHTISOORGWEBWWWISOORGPUBLISHEDINSWITZERLANDIIISO2009ALLRIGHTSRESERVEDCOPYRIGHTINTERNATIONALORGANIZATIONFORSTANDARDIZATIONPROVIDEDBYIHSUNDERLICENSEWITHISONOTFORRESALENOREPRODUCTIONORNETWORKINGPERMITTEDWITHOUTLICENSEFROMIHS,ISO85962009EISO2009ALLRIGHTSRESERVEDIIIFOREWORDISOTHEINTERNATIONALORGANIZATIONFORSTANDARDIZATIONISAWORLDWIDEFEDERATIONOFNATIONALSTANDARDSBODIESISOMEMBERBODIESTHEWORKOFPREPARINGINTERNATIONALSTANDARDSISNORMALLYCARRIEDOUTTHROUGHISOTECHNICALCOMMITTEESEACHMEMBERBODYINTERESTEDINASUBJECTFORWHICHATECHNICALCOMMITTEEHASBEENESTABLISHEDHASTHERIGHTTOBEREPRESENTEDONTHATCOMMITTEEINTERNATIONALORGANIZATIONS,GOVERNMENTALANDNONGOVERNMENTAL,INLIAISONWITHISO,ALSOTAKEPARTINTHEWORKISOCOLLABORATESCLOSELYWITHTHEINTERNATIONALELECTROTECHNICALCOMMISSIONIECONALLMATTERSOFELECTROTECHNICALSTANDARDIZATIONINTERNATIONALSTANDARDSAREDRAFTEDINACCORDANCEWITHTHERULESGIVENINTHEISO/IECDIRECTIVES,PART2THEMAINTASKOFTECHNICALCOMMITTEESISTOPREPAREINTERNATIONALSTANDARDSDRAFTINTERNATIONALSTANDARDSADOPTEDBYTHETECHNICALCOMMITTEESARECIRCULATEDTOTHEMEMBERBODIESFORVOTINGPUBLICATIONASANINTERNATIONALSTANDARDREQUIRESAPPROVALBYATLEAST75OFTHEMEMBERBODIESCASTINGAVOTEATTENTIONISDRAWNTOTHEPOSSIBILITYTHATSOMEOFTHEELEMENTSOFTHISDOCUMENTMAYBETHESUBJECTOFPATENTRIGHTSISOSHALLNOTBEHELDRESPONSIBLEFORIDENTIFYINGANYORALLSUCHPATENTRIGHTSISO8596WASPREPAREDBYTECHNICALCOMMITTEEISO/TC172,OPTICSANDPHOTONICS,SUBCOMMITTEESC7,OPHTHALMICOPTICSANDINSTRUMENTSTHISSECONDEDITIONCANCELSANDREPLACESTHEFIRSTEDITIONISO85961994,WHICHHASUNDERGONEMINORREVISIONTOTAKEINTOACCOUNTTHEWITHDRAWALWITHOUTREPLACEMENTOFISO85971994,OPTICSANDOPTICALINSTRUMENTSVISUALACUITYTESTINGMETHODOFCORRELATINGOPTOTYPESCOPYRIGHTINTERNATIONALORGANIZATIONFORSTANDARDIZATIONPROVIDEDBYIHSUNDERLICENSEWITHISONOTFORRESALENOREPRODUCTIONORNETWORKINGPERMITTEDWITHOUTLICENSEFROMIHS,COPYRIGHTINTERNATIONALORGANIZATIONFORSTANDARDIZATIONPROVIDEDBYIHSUNDERLICENSEWITHISONOTFORRESALENOREPRODUCTIONORNETWORKINGPERMITTEDWITHOUTLICENSEFROMIHS,INTERNATIONALSTANDARDISO85962009EISO2009ALLRIGHTSRESERVED1OPHTHALMICOPTICSVISUALACUITYTESTINGSTANDARDOPTOTYPEANDITSPRESENTATION1SCOPETHISINTERNATIONALSTANDARDSPECIFIESARANGEOFLANDOLTRINGOPTOTYPESANDDESCRIBESAMETHODFORMEASURINGDISTANCEVISUALACUITYUNDERDAYLIGHTCONDITIONSFORTHEPURPOSESOFCERTIFICATIONORLICENSINGITISNEITHERINTENDEDASASTANDARDFORCLINICALMEASUREMENTSNORFORTHECERTIFICATIONOFBLINDNESSORPARTIALSIGHTFORTHEPURPOSESOFMEASURINGVISUALACUITY,THESTANDARDOPTOTYPESHOULDBEUSEDFORCLINICALUSE,SEETHERECOMMENDATIONPREPAREDBYTHEVISUALFUNCTIONSCOMMITTEEOFTHEINTERNATIONALCOUNCILOFOPHTHALMOLOGY12NORMATIVEREFERENCESTHEFOLLOWINGREFERENCEDDOCUMENTSAREINDISPENSABLEFORTHEAPPLICATIONOFTHISDOCUMENTFORDATEDREFERENCES,ONLYTHEEDITIONCITEDAPPLIESFORUNDATEDREFERENCES,THELATESTEDITIONOFTHEREFERENCEDDOCUMENTINCLUDINGANYAMENDMENTSAPPLIESISO31973,PREFERREDNUMBERSSERIESOFPREFERREDNUMBERS3STANDARDOPTOTYPETHESTANDARDOPTOTYPESHALLBETHELANDOLTRINGASDETAILEDINTABLE1ANDASSHOWNINFIGURE1THEVISUALACUITYGRADE1SHALLBEREPRESENTEDBYALANDOLTRINGWHOSEOUTERDIAMETER,D,SUBTENDSANANGLEOF5ANDWHOSEWIDTH,ASWELLASTHEGAPINITSCONTINUITY,SUBTENDSANANGLEOF1ATTHEDESIGNATEDVIEWINGDISTANCETHELANDOLTRINGSHALLBECAPABLEOFBEINGPRESENTEDINEIGHTDIFFERENTPOSITIONSSEE624VISUALACUITYGRADESANDSTANDARDOPTOTYPEGRADESTHEVISUALACUITYGRADESSHALLBEASGIVENINTABLE1ANDSHALLBEEXPRESSEDASTHERECIPROCALOFTHEGAPWIDTHMEASUREDINMINUTESOFARCTHEACUITYVALUESFORTHESIZEOFTHEOPTOTYPESHALLBEGRADUATEDLOGARITHMICALLYTHEQUOTIENTOFTHESIZEOFTHEOPTOTYPEANDTHATOFTHENEXTSMALLERONESHALLBE10101,2589SERIESOFPREFERR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