BS EN ISO 21987-2009

BSENISO219872009ICS1104070NOCOPYINGWITHOUTBSIPERMISSIONEXCEPTASPERMITTEDBYCOPYRIGHTLAWBRITISHSTANDARDOPHTHALMICOPTICSMOUNTEDSPECTACLELENSESISO219872009BOUGHTBYMARTINWHITE,BROWNANDWHITE,ON04/02/20101347LATESTVERSIONNOTTOBEDISTRIBUTED/NETWORKEDFORMULTIUSERACCESSWWWBSIGROUPCOM/LICENSEBSITHISBRITISHSTANDARDWASPUBLISHEDUNDERTHEAUTHORITYOFTHESTANDARDSPOLICYANDSTRATEGYCOMMITTEEON31DECEMBER2009BSI2009ISBN9780580634987AMENDMENTS/CORRIGENDAISSUEDSINCEPUBLICATIONDATECOMMENTSBSENISO219872009NATIONALFOREWORDTHISBRITISHSTANDARDISTHEUKIMPLEMENTATIONOFENISO219872009ITSUPERSEDESBS273811998WHICHWILLBEWITHDRAWNON1FEBRUARY2010THEMAJORDIFFERENCESBETWEENBSENISO219872009ANDBS273811998AREINTHETOLERANCESONTHECYLINDERAXISDIRECTIONTHEPRISMIMBALANCERELATIVEPRISMERRORFORPAIRSOFSINGLEVISIONANDMULTIFOCALLENSESANDTHERELIANCEONTHEOPTICALCENTRATIONOFTHEUNCUTLENSESBEFOREGLAZINGFORPROGRESSIVEPOWERLENSESANDTHEIRCORRECTPOSITIONINGDURINGMOUNTINGTHEUKPARTICIPATIONINITSPREPARATIONWASENTRUSTEDTOTECHNICALCOMMITTEECH/172/3,SPECTACLESALISTOFORGANIZATIONSREPRESENTEDONTHISCOMMITTEECANBEOBTAINEDONREQUESTTOITSSECRETARYTHISPUBLICATIONDOESNOTPURPORTTOINCLUDEALLTHENECESSARYPROVISIONSOFACONTRACTUSERSARERESPONSIBLEFORITSCORRECTAPPLICATIONCOMPLIANCEWITHABRITISHSTANDARDCANNOTCONFERIMMUNITYFROMLEGALOBLIGATIONSBOUGHTBYMARTINWHITE,BROWNANDWHITE,ON04/02/20101347LATESTVERSIONNOTTOBEDISTRIBUTED/NETWORKEDFORMULTIUSERACCESSWWWBSIGROUPCOM/LICENSEBSIEUROPEANSTANDARDNORMEEUROPENNEEUROPISCHENORMENISO21987OCTOBER2009ICS1104070ENGLISHVERSIONOPHTHALMICOPTICSMOUNTEDSPECTACLELENSESISO219872009OPTIQUEOPHTALMIQUEVERRESOPHTALMIQUESMONTSISO219872009AUGENOPTIKFERTIGMONTIERTEKORREKTIONSBRILLENGLSERISO219872009THISEUROPEANSTANDARDWASAPPROVEDBYCENON17SEPTEMBER2009CENMEMBERSAREBOUNDTOCOMPLYWITHTHECEN/CENELECINTERNALREGULATIONSWHICHSTIPULATETHECONDITIONSFORGIVINGTHISEUROPEANSTANDARDTHESTATUSOFANATIONALSTANDARDWITHOUTANYALTERATIONUPTODATELISTSANDBIBLIOGRAPHICALREFERENCESCONCERNINGSUCHNATIONALSTANDARDSMAYBEOBTAINEDONAPPLICATIONTOTHECENMANAGEMENTCENTREORTOANYCENMEMBERTHISEUROPEANSTANDARDEXISTSINTHREEOFFICIALVERSIONSENGLISH,FRENCH,GERMANAVERSIONINANYOTHERLANGUAGEMADEBYTRANSLATIONUNDERTHERESPONSIBILITYOFACENMEMBERINTOITSOWNLANGUAGEANDNOTIFIEDTOTHECENMANAGEMENTCENTREHASTHESAMESTATUSASTHEOFFICIALVERSIONSCENMEMBERSARETHENATIONALSTANDARDSBODIESOFAUSTRIA,BELGIUM,BULGARIA,CYPRUS,CZECHREPUBLIC,DENMARK,ESTONIA,FINLAND,FRANCE,GERMANY,GREECE,HUNGARY,ICELAND,IRELAND,ITALY,LATVIA,LITHUANIA,LUXEMBOURG,MALTA,NETHERLANDS,NORWAY,POLAND,PORTUGAL,ROMANIA,SLOVAKIA,SLOVENIA,SPAIN,SWEDEN,SWITZERLANDANDUNITEDKINGDOMEUROPEANCOMMITTEEFORSTANDARDIZATIONCOMITEUROPENDENORMALISATIONEUROPISCHESKOMITEEFRNORMUNGMANAGEMENTCENTREAVENUEMARNIX17,B1000BRUSSELS2009CENALLRIGHTSOFEXPLOITATIONINANYFORMANDBYANYMEANSRESERVEDWORLDWIDEFORCENNATIONALMEMBERSREFNOENISO219872009EBOUGHTBYMARTINWHITE,BROWNANDWHITE,ON04/02/20101347LATESTVERSIONNOTTOBEDISTRIBUTED/NETWORKEDFORMULTIUSERACCESSWWWBSIGROUPCOM/LICENSEBSIBSENISO219872009ENISO219872009E3FOREWORDTHISDOCUMENTENISO219872009HASBEENPREPAREDBYTECHNICALCOMMITTEEISO/TC172“OPTICSANDPHOTONICS“INCOLLABORATIONWITHTECHNICALCOMMITTEECEN/TC170“OPHTHALMICOPTICS”THESECRETARIATOFWHICHISHELDBYDINTHISEUROPEANSTANDARDSHALLBEGIVENTHESTATUSOFANATIONALSTANDARD,EITHERBYPUBLICATIONOFANIDENTICALTEXTORBYENDORSEMENT,ATTHELATESTBYAPRIL2010,ANDCONFLICTINGNATIONALSTANDARDSSHALLBEWITHDRAWNATTHELATESTBYAPRIL2010ATTENTIONISDRAWNTOTHEPOSSIBILITYTHATSOMEOFTHEELEMENTSOFTHISDOCUMENTMAYBETHESUBJECTOFPATENTRIGHTSCENAND/ORCENELECSHALLNOTBEHELDRESPONSIBLEFORIDENTIFYINGANYORALLSUCHPATENTRIGHTSTHISDOCUMENTHASBEENPREPAREDUNDERAMANDATEGIVENTOCENBYTHEEUROPEANCOMMISSIONANDTHEEUROPEANFREETRADEASSOCIATION,ANDSUPPORTSESSENTIALREQUIREMENTSOFEUDIRECTIVEFORRELATIONSHIPWITHEUDIRECTIVE,SEEINFORMATIVEANNEXZA,WHICHISANINTEGRALPARTOFTHISDOCUMENTACCORDINGTOTHECEN/CENELECINTERNALREGULATIONS,THENATIONALSTANDARDSORGANIZATIONSOFTHEFOLLOWINGCOUNTRIESAREBOUNDTOIMPLEMENTTHISEUROPEANSTANDARDAUSTRIA,BELGIUM,BULGARIA,CYPRUS,CZECHREPUBLIC,DENMARK,ESTONIA,FINLAND,FRANCE,GERMANY,GREECE,HUNGARY,ICELAND,IRELAND,ITALY,LATVIA,LITHUANIA,LUXEMBOURG,MALTA,NETHERLANDS,NORWAY,POLAND,PORTUGAL,ROMANIA,SLOVAKIA,SLOVENIA,SPAIN,SWEDEN,SWITZERLANDANDTHEUNITEDKINGDOMENDORSEMENTNOTICETHETEXTOFISO219872009HASBEENAPPROVEDBYCENASAENISO219872009WITHOUTANYMODIFICATIONBOUGHTBYMARTINWHITE,BROWNANDWHITE,ON04/02/20101347LATESTVERSIONNOTTOBEDISTRIBUTED/NETWORKEDFORMULTIUSERACCESSWWWBSIGROUPCOM/LICENSEBSIBSENISO219872009ENISO219872009E4ANNEXZAINFORMATIVERELATIONSHIPBETWEENTHISINTERNATIONALSTANDARDANDTHEESSENTIALREQUIREMENTSOFEUDIRECTIVE93/42/EECTHISINTERNATIONALSTANDARDHASBEENPREPAREDUNDERAMANDATEGIVENTOCENBYTHEEUROPEANCOMMISSIONANDTHEEUROPEANFREETRADEASSOCIATIONTOPROVIDEONEMEANSOFCONFORMINGTOESSENTIALREQUIREMENTSOFTHENEWAPPROACHDIRECTIVE93/42/EEC,MEDICALDEVICESGENERALONCETHISSTANDARDISCITEDINTHEOFFICIALJOURNALOFTHEEUROPEANUNIONUNDERTHATDIRECTIVEANDHASBEENIMPLEMENTEDASANATIONALSTANDARDINATLEASTONEMEMBERSTATE,COMPLIANCEWITHTHENORMATIVECLAUSESOFTHISSTANDARDGIVENINTABLEZA1CONFERS,WITHINTHELIMITSOFTHESCOPEOFTHISSTANDARD,APRESUMPTIONOFCONFORMITYWITHTHECORRESPONDINGESSENTIALREQUIREMENTSOFTHATDIRECTIVEANDASSOCIATEDEFTAREGULATIONSTABLEZA1CORRESPONDENCEBETWEENTHISINTERNATIONALSTANDARDANDDIRECTIVE93/42/EECCLAUSES/SUBCLAUSESOFTHISINTERNATIONALSTANDARDESSENTIALREQUIREMENTSERSOFEUDIRECTIVE93/42/EECQUALIFYINGREMARKS/NOTES521,2,3,4,6,6A,71,92,93THESEERSARECOVEREDBYNORMATIVEREFERENCETOIS54,5537,8131,133THESEERSARECOVEREDBYCLAUSE7,ANDBYTHENORMATIVEREFERENCETOISO148892003INCLAUSE8NOTEER133AISONLYPARTLYADDRESSEDINISO148892003WARNINGOTHERREQUIREMENTSANDOTHEREUDIRECTIVESMAYBEAPPLICABLETOTHEPRODUCTSFALLINGWITHINTHESCOPEOFTHISSTANDARDBOUGHTBYMARTINWHITE,BROWNANDWHITE,ON04/02/20101347LATESTVERSIONNOTTOBEDISTRIBUTED/NETWORKEDFORMULTIUSERACCESSWWWBSIGROUPCOM/LICENSEBSIBSENISO219872009ISO219872009EISO2009ALLRIGHTSRESERVEDIIICONTENTSPAGEFOREWORDIV1SCOPE12NORMATIVEREFERENCES13TERMSANDDEFINITIONS14CLASSIFICATION25REQUIREMENTS251REFERENCETEMPERATURE252LENSESUSEDINMANUFACTURINGCOMPLETESPECTACLES253OPTICALREQUIREMENTS254THICKNESSTOLERANCE655POSITIONINGTOLERANCES66TESTMETHODS861GENERAL862MEASUREMENTMETHODFORTHEBACKVERTEXPOWEROFSINGLEVISIONLENSESANDTHEDISTANCEPORTIONOFMULTIFOCALANDPROGRESSIVEPOWERLENSESANDNEARPORTIONOFDEGRESSIVEPOWERLENSES863MEASUREMENTMETHODFORCYLINDERAXIS864ADDITIONPOWERMEASUREMENT865METHODFORMEASURINGPOSITIONANDTILT1066MATERIALANDSURFACEQUALITY1067PRISMIMBALANCERELATIVEPRISMERRORMEASUREMENTMETHODFORPAIRSOFSINGLEVISIONANDMULTIFOCALLENSES107MARKINGFORPROGRESSIVEPOWERANDDEGRESSIVEPOWERLENSES1071PERMANENTMARKING1072NONPERMANENTMARKING118IDENTIFICATION119REFERENCETOISO2198711ANNEXAINFORMATIVEMATERIALANDSURFACEQUALITY12ANNEXBINFORMATIVERECOMMENDATIONSONMOUNTING13ANNEXCINFORMATIVEALTERNATIVEMETHODSFORMEASURINGPRISMIMBALANCERELATIVEPRISMERRORFORPAIRSOFSINGLEVISIONANDMULTIFOCALLENSES15BIBLIOGRAPHY17BOUGHTBYMARTINWHITE,BROWNANDWHITE,ON04/02/20101347LATESTVERSIONNOTTOBEDISTRIBUTED/NETWORKEDFORMULTIUSERACCESSWWWBSIGROUPCOM/LICENSEBSIBSENISO219872009ISO219872009EIVISO2009ALLRIGHTSRESERVEDFOREWORDISOTHEINTERNATIONALORGANIZATIONFORSTANDARDIZATIONISAWORLDWIDEFEDERATIONOFNATIONALSTANDARDSBODIESISOMEMBERBODIESTHEWORKOFPREPARINGINTERNATIONALSTANDARDSISNORMALLYCARRIEDOUTTHROUGHISOTECHNICALCOMMITTEESEACHMEMBERBODYINTERESTEDINASUBJECTFORWHICHATECHNICALCOMMITTEEHASBEENESTABLISHEDHASTHERIGHTTOBEREPRESENTEDONTHATCOMMITTEEINTERNATIONALORGANIZATIONS,GOVERNMENTALANDNONGOVERNMENTAL,INLIAISONWITHISO,ALSOTAKEPARTINTHEWORKISOCOLLABORATESCLOSELYWITHTHEINTERNATIONALELECTROTECHNICALCOMMISSIONIECONALLMATTERSOFELECTROTECHNICALSTANDARDIZATIONINTERNATIONALSTANDARDSAREDRAFTEDINACCORDANCEWITHTHERULESGIVENINTHEISO/IECDIRECTIVES,PART2THEMAINTASKOFTECHNICALCOMMITTEESISTOPREPAREINTERNATIONALSTANDARDSDRAFTINTERNATIONALSTANDARDSADOPTEDBYTHETECHNICALCOMMITTEESARECIRCULATEDTOTHEMEMBERBODIESFORVOTINGPUBLICATIONASANINTERNATIONALSTANDARDREQUIRESAPPROVALBYATLEAST75OFTHEMEMBERBODIESCASTINGAVOTEATTENTIONISDRAWNTOTHEPOSSIBILITYTHATSOMEOFTHEELEMENTSOFTHISDOCUMENTMAYBETHESUBJECTOFPATENTRIGHTSISOSHALLNOTBEHELDRESPONSIBLEFORIDENTIFYINGANYORALLSUCHPATENTRIGHTSISO21987WASPREPAREDBYTECHNICALCOMMITTEEISO/TC172,OPTICSANDPHOTONICS,SUBCOMMITTEESC7,OPHTHALMICOPTICSANDINSTRUMENTSBOUGHTBYMARTINWHITE,BROWNANDWHITE,ON04/02/20101347LATESTVERSIONNOTTOBEDISTRIBUTED/NETWORKEDFORMULTIUSERACCESSWWWBSIGROUPCOM/LICENSEBSIBSENISO219872009INTERNATIONALSTANDARDISO219872009EISO2009ALLRIGHTSRESERVED1OPHTHALMICOPTICSMOUNTEDSPECTACLELENSES1SCOPETHISINTERNATIONALSTANDARDSPECIFIESREQUIREMENTSFORMOUNTEDSPECTACLELENSESRELATIVETOTHEPRESCRIPTIONORDER2NORMATIVEREFERENCESTHEFOLLOWINGREFERENCEDDOCUMENTSAREINDISPENSABLEFORTHEAPPLICATIONOFTHISDOCUMENTFORDATEDREFERENCES,ONLYTHEEDITIONCITEDAPPLIESFORUNDATEDREFERENCES,THELATESTEDITIONOFTHEREFERENCEDDOCUMENTINCLUDINGANYAMENDMENTSAPPLIESISO7944,OPTICSANDOPTICALINSTRUMENTSREFERENCEWAVELENGTHSISO8429,OPTICSANDOPTICALINSTRUMENTSOPHTHALMOLOGYGRADUATEDDIALSCALEISO8598,OPTICSANDOPTICALINSTRUMENTSFOCIMETERSISO8624,OPHTHALMICOPTICSSPECTACLEFRAMESMEASURINGSYSTEMANDTERMINOLOGYISO89801,OPHTHALMICOPTICSUNCUTFINISHEDSPECTACLELENSESPART1SPECIFICATIONSFORSINGLEVISIONANDMULTIFOCALLENSESISO89802,OPHTHALMICOPTICSUNCUTFINISHEDSPECTACLELENSESPART2SPECIFICATIONSFORPROGRESSIVEPOWERLENSESISO89803,OPHTHALMICOPTICSUNCUTFINISHEDSPECTACLELENSESPART3TRANSMITTANCESPECIFICATIONSANDTESTMETHODSISO89804,OPHTHALMICOPTICSUNCUTFINISHEDSPECTACLELENSESPART4SPECIFICATIONSANDTESTMETHODSFORANTIREFLECTIVECOATINGSISO89805,OPHTHALMICOPTICSUNCUTFINISHEDSPECTACLELENSESPART5MINIMUMREQUIREMENTSFORSPECTACLELENSSURFACESCLAIMEDTOBEABRASIONRESISTANTISO13666,OPHTHALMICOPTICSSPECTACLELENSESVOCABULARYISO148892003,OPHTHALMICOPTICSSPECTACLELENSESFUNDAMENTALREQUIREMENTSFORUNCUTFINISHEDLENSES3TERMSANDDEFINITIONSFORTHEPURPOSESOFTHISDOCUMENT,THETERMSANDDEFINITIONSGIVENINISO13666APPLYBOUGHTBYMARTINWHITE,BROWNANDWHITE,ON04/02/20101347LATESTVERSIONNOTTOBEDISTRIBUTED/NETWORKEDFORMULTIUSERACCESSWWWBSIGROUPCOM/LICENSEBSIBSENISO219872009ISO219872009E2ISO2009ALLRIGHTSRESERVED4CLASSIFICATIONFINISHED,MOUNTEDLENSESARECLASSIFIEDASFOLLOWSASINGLEVISIONFINISHEDLENSESBMULTIFOCALFINISHEDLENSESCPROGRESSIVEPOWERANDDEGRESSIVEPOWERFINISHEDLENSES5REQUIREMENTS51REFERENCETEMPERATURETHETOLERANCESSHALLAPPLYATATEMPERATUREOF23C5C52LENSESUSEDINMANUFACTURINGCOMPLETESPECTACLESLENSESUSEDINMANUFACTURINGCOMPLETESPECTACLESSHALLMEETTHEREQUIREMENTSOFISO148892003,41,42,431,432AND45LENSESSHALLALSOHAVEBEENSHOWNTOMEETTHEREQUIREMENTSISO148892003,44UNLESSANATIONALSTANDARDORLAWSPECIFIESMECHANICALSTRENGTHREQUIREMENTS,INWHICHCASETHENATIONALSTANDARDORLAWWILLTAKEPRECEDENCEISO148892003,41REQUIRESTHATTHEUNCUTFINISHEDLENSESUSEDINMANUFACTURINGCOMPLETESPECTACLESCOMPLYWITHTHERELEVANTPARTSOFISO8980LENSESINMOUNTEDSPECTACLESSHALLALSOCOMPLYWITHOTHERREQUIREMENTSOFTHEPRESCRIPTIONORDERNOTINCLUDEDINTHISINTERNATIONALSTANDARD53OPTICALREQUIREMENTS531GENERALTHEOPTICALCHARACTERISTICSSHALLBEDETERMINEDUSINGAFOCIMETERCOMPLYINGWITHISO8598WHERETHEPOWERISMEASUREDINTHEPRESENCEOFMORETHAN0,50THEOPTICALPOWERSHALLBETHEOFFAXISPOWERTHEOPTICALTOLERANCESSHALLAPPLYATTHEREFERENCEPOINTSOFTHELENSESATEITHEROFTHEREFERENCEWAVELENGTHSSPECIFIEDINISO7944IFTHEMANUFACTURERHASAPPLIEDCORRECTIONSTOCOMPENSATEFORTHE“ASWORN”POSITION,THENTHETOLERANCESSHALLAPPLYTOTHIS“ASWORN”CORRECTEDDIOPTRICPOWER532BACKVERTEXPOWERTOLERANCETHETOLERANCESINTABLE1APPLYTOALLSINGLEVISIONLENSESANDTHEDISTANCEPORTIONOFMULTIFOCALLENSES,INCLUDINGTHOSEWITHASPHERICALORATOROIDALSURFACESTHETOLERANCESINTABLE2APPLYTOTHEDISTANCEPORTIONOFPROGRESSIVEPOWERLENSESANDTHENEARPORTIONOFDEGRESSIVEPOWERLENSESTHEBACKVERTEXPOWERSHALLBEMEASUREDUSINGTHEMETHODDESCRIBEDIN62533CYLINDERAXISDIRECTIONTOLERANCETHEDIRECTIONOFTHECYLINDERAXISSHALLBEMEASUREDUSINGTHEMETHODDESCRIBEDIN63,ANDSHALLBESPECIFIEDINACCORDANCEWITHISO8429THETOLERANCESONTHEDIRECTIONOFTHECYLINDERAXISARESPECIFIEDINTABLE3BOUGHTBYMARTINWHITE,BROWNANDWHITE,ON04/02/20101347LATESTVERSIONNOTTOBEDISTRIBUTED/NETWORKEDFORMULTIUSERACCESSWWWBSIGROUPCOM/LICENSEBSIBSENISO219872009ISO219872009EISO2009ALLRIGHTSRESERVED3NOTE1TOALLOWFORSOMETOLERANCEINMOUNTING,THETOLERANCEONTHEDIRECTIONOFCYLINDERAXISHASGENERALLYBEENINCREASEDOVERTHETOLERANCESFOUNDINTHEISOUNCUTFINISHEDLENSSTANDARDSISO89801ANDISO89802NOTE2COMPENSATIONFORTHE“ASWORN”POSITIONMIGHTRESULTINCYLINDERPOWERSOFLESSTHAN0,12D,INWHICHCASETHEREARENOAPPLICABLEAXISTOLERANCES534ADDITIONPOWERTOLERANCEFORMULTIFOCALANDPROGRESSIVEPOWERLENSESTHEADDITIONPOWERSHALLBEMEASUREDUSINGTHEMETHODDESCRIBEDIN64THETOLERANCESONADDITIONPOWERARESPECIFIEDINTABLE4TABLE1TOLERANCESONTHEBACKVERTEXPOWEROFSINGLEVISIONANDMULTIFOCALLENSESVALUESINDIOPTRESTOLERANCEOFTHECYLINDRICALPOWERPOWEROFPRINCIPALMERIDIANWITHHIGHERABSOLUTEBACKVERTEXPOWERTOLERANCEONTHEBACKVERTEXPOWEROFEACHPRINCIPALMERIDIANW0,00ANDU0,750,75ANDU4,004,00ANDU6,006,00W0,00ANDU3,000,120,090,120,183,00ANDU6,000,120,120,120,180,256,00ANDU9,000,120,120,180,180,259,00ANDU12,000,180,120,180,250,2512,00ANDU20,000,250,180,250,250,2520,000,370,250,250,370,37TABLE2TOLERANCESONTHEBACKVERTEXPOWEROFPROGRESSIVEANDDEGRESSIVEPOWERLENSESVALUESINDIOPTRESTOLERANCEOFTHECYLINDRICALPOWERPOWEROFPRINCIPALMERIDIANWITHHIGHERABSOLUTEBACKVERTEXPOWERTOLERANCEONTHEBACKVERTEXPOWEROFEACHPRINCIPALMERIDIANW0,00ANDU0,750,75ANDU4,004,00ANDU6,006,00W0,00ANDU6,000,120,120,180,180,256,00ANDU9,000,180,180,180,180,259,00ANDU12,000,180,180,180,250,2512,00ANDU20,000,250,180,250,250,2520,000,370,250,250,370,37TABLE3TOLERANCESONTHEDIRECTIONOFCYLINDERAXISABSOLUTECYLINDRICALPOWERDIOPTRESW0,125ANDU0,250,25ANDU0,500,50ANDU0,750,75ANDU1,501,50ANDU2,502,50TOLERANCEONTHEAXISDIRECTIONDEGREES1696432TABLE4TOLERANCESONTHEADDITIONPOWERFORMULTIFOCALANDPROGRESSIVEPOWERLENSESVALUESINDIOPTRESVALUEOFTHEADDITIONPOWERU4,004,00TOLERANCE0,120,18BOUGHTBYMARTINWHITE,BROWNANDWHITE,ON04/02/20101347LATESTVERSIONNOTTOBEDISTRIBUTED/NETWORKEDFORMULTIUSERACCESSWWWBSIGROUPCOM/LICENSEBSIBSENISO219872009ISO219872009E4ISO2009ALLRIGHTSRESERVED535PRISMIMBALANCERELATIVEPRISMERRORFORPAIRSOFSINGLEVISIONANDMULTIFOCALLENSESAFTERNEUTRALIZINGORALLOWINGFORANYPRESCRIBEDPRISM,THETOLERANCESASGIVENINTABLE5SHALLBEMETWHENTESTEDINACCORDANCEWITHTHEMETHODGIVENIN67TODETERMINETHEPRISMIMBALANCE1RESOLVEANYORDEREDPRISMTOITSHORIZONTALANDVERTICALCOMPONENTS2FINDFOURPRINCIPALPOWERSTWOINEACHLENS3IDENTIFYTHEMINIMUMABSOLUTEPOWERFROMTHEFOURPRINCIPALPOWERS4ENTERFIGURE1WITHTHATPOWERTHEXAXISANDFINDHORIZONTALIMBALANCETOLERANCETHEYAXIS,USINGTHECURVEREPRESENTINGTHERELEVANTRANGETHATCONTAINSTHEHIGHERVALUEORDEREDPRISMCOMPONENT5ENTERFIGURE2WITHTHATPOWERTHEXAXISANDFINDVERTICALIMBALANCETOLERANCETHEYAXIS,USINGTHECURVEREPRESENTINGTHERELEVANTRANGETHATCONTAINSTHEHIGHERVALUEORDEREDPRISMCOMPONENTTABLE5PRISMIMBALANCERELATIVEPRISMERRORTOLERANCESFORSINGLEVISIONANDMULTIFOCALLENSESHIGHERABSOLUTEORDEREDCOMPONENTPRISMVALUETOLERANCEONTHEHORIZONTALCOMPONENTRELATIVETOTHEORDEREDCENTRATIONDISTANCETOLERANCEONTHEVERTICALCOMPONENTRELATIVETOTHEORDEREDCENTRATIONDISTANCEW0,00TOU2,00FORPOWERSAW0,00TOU3,25D0,67FORPOWERSA3,25DTHEPRISMATICEFFECTOF2,0MMDISPLACEMENTFORPOWERSAW0,00TOU5,00D0,50FORPOWERSA5,00DTHEPRISMATICEFFECTOF1,0MMDISPLACEMENT2,00TOU10,00FORPOWERSAW0,00TOU3,25D1,00FORPOWERSA3,25D0,33THEPRISMATICEFFECTOF2,0MMDISPLACEMENTFORPOWERSAW0,00TOU5,00D0,75FORPOWERSA5,00D0,25THEPRISMATICEFFECTOF1,0MMDISPLACEMENT10,00FORPOWERSAW0,00TOU3,25D1,25FORPOWERSA3,25D0,58THEPRISMATICEFFECTOF2,0MMDISPLACEMENTFORPOWERSAW0,00TOU5,00D1,00FORPOWERSA5,00D0,50THEPRISMATICEFFECTOF1,0MMDISPLACEMENTATHESETOLERANCESAREAPPLIEDTOTHELOWESTABSOLUTEPRINCIPALPOWEROFTHEPAIROFLENSES536PRISMIMBALANCERELATIVEPRISMERRORFORPROGRESSIVEPOWERLENSESANDDEGRESSIVEPOWERLENSESPOSITIONINGOFPROGRESSIVEPOWERLENSESANDDEGRESSIVEPOWERLENSESWITHINTHESPECIFICATIONSOFTHISINTERNATIONALSTANDARDWILLPRODUCEPRISMIMBALANCEERRORSCONSISTENTWITHWEARERNEEDSITISESSENTIALTHATTHEINDIVIDUALPRISMERRORSOFEACHLENS,MEASUREDATTHEPRISMREFERENCEPOINT,DONOTEXCEEDTHETOLERANCESGIVENINISO89802BOUGHTBYMARTINWHITE,BROWNANDWHITE,ON04/02/20101347LATESTVERSIONNOTTOBEDISTRIBUTED/NETWORKEDFORMULTIUSERACCESSWWWBSIGROUPCOM/LICENSEBSIBSENISO219872009ISO219872009EISO2009ALLRIGHTSRESERVED5KEY110,0022,00TOU10,003W0,00TOU2,00XMINIMUMABSOLUTEPRINCIPALPOWERDIOPTRES,DYPRISMIMBALANCETOLERANCEPRISMDIOPTRES,FIGURE1HORIZONTALPRISMIMBALANCERELATIVEPRISMERRORTOLERANCESFORLENSESWITHHIGHERABSOLUTEORDEREDCOMPONENTPRISMVALUESOFW0,00TOU2,00,2,00TOU10,00AND10,00BOUGHTBYMARTINWHITE,BROWNANDWHITE,ON04/02/20101347LATESTVERSIONNOTTOBEDISTRIBUTED/NETWORKEDFORMULTIUSERACCESSWWWBSIGROUPCOM/LICENSEBSIBSENISO219872009ISO219872009E6ISO2009ALLRIGHTSRESERVEDKEY110,0022,00TOU10,003W0,00TOU2,00XMINIMUMABSOLUTEPRINCIPALPOWERDIOPTRES,DYPRISMIMBALANCETOLERANCEPRISMDIOPTRES,FIGURE2VERTICALPRISMIMBALANCERELATIVEPRISMERRORTOLERANCESFORLENSESWITHHIGHERABSOLUTEORDEREDCOMPONENTPRISMVALUESOFW0,00TOU2,00,2,00TOU10,00AND10,0054THICKNESSTOLERANCETHETHICKNESSOFTHELENSMAYBESPECIFIEDBYTHEMANUFACTURERORBEAGREEDBETWEENTHEORDERERANDTHESUPPLIERTHICKNESSSHALLBEMEASUREDATTHEREFERENCEPOINTOFTHEFRONTSURFACEANDNORMALTOTHISSURFACEITSHALLNOTDEVIATEFROMTHEORDEREDORAGREEDVALUEBYMORETHAN0,3MM55POSITIONINGTOLERANCES551MULTIFOCALLENSES5511VERTICALPOSITIONSORHEIGHTSOFTHESEGMENTSTHESEGMENTEXTREMEPOINTPOSITIONSSINFIGURE3ORSEGMENTHEIGHTSHINFIGURE3SHALLBEWITHIN1,0MMOFTHATORDEREDINADDITION,THEDIFFERENCEBETWEENSEGMENTHEIGHTSFORTHEMOUNTEDPAIRSHALLNOTEXCEED1,0MMRELATIVETOANYDIFFERENCEORDEREDMEASUREMENTSHALLBEMADEUSINGTHEMETHODSPECIFIEDIN65NOTETHEMEASUREMENTPOINTFORANESTYLEMULTIFOCALSEGMENTISTHEPOINTONTHEDIVIDINGLINEATWHICHTHEHEIGHTOFTHELEDGEBETWEENTHEDISTANCEANDNEARPORTIONSISATAMINIMUMBOUGHTBYMARTINWHITE,BROWNANDWHITE,ON04/02/20101347LATESTVERSIONNOTTOBEDISTRIBUTED/NETWORKEDFORMULTIUSERACCESSWWWBSIGROUPCOM/LICENSEBSIBSENISO219872009ISO219872009EISO2009ALLRIGHTSRESERVED75512HORIZONTALPOSITIONOFTHESEGMENTSTHEHORIZONTALPOSITIONOFTHESEGMENTEXTREMEPOINTSSHALLBEI1,0MMFROMTHEORDEREDMONOCULARCENTRATIONPOINTSPWHEREIISTHEGEOMETRICALINSETSEEFIGURE3MEASUREMENTSHALLBEMADEUSINGTHEMETHODSPECIFIEDIN65NOTE1THEHORIZONTALPOSITIONOFBOTHSEGMENTSSHOULDAPPEARSY