1、Ophthalmic optics Contact lensesPart 2: Tolerances (ISO 18369-2:2017)BS EN ISO 18369-2:2017BSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06National forewordThis British Standard is the UK implementation of EN ISO 18369-2:2017. It is identical to ISO 18369-2:2017. It
2、supersedes BS EN ISO 18369-2:2012, which is withdrawn.The UK participation in its preparation was entrusted to Technical Committee CH/172/9, Contact lenses and contact lens care products.A list of organizations represented on this committee can be obtained on request to its secretary.This publicatio
3、n does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. The British Standards Institution 2017 Published by BSI Standards Limited 2017ISBN 978 0 580 87558 8ICS 11.040.70; 01.040.11Compliance with a British Standard cannot confer im
4、munity from legal obligations.This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 September 2017.Amendments/corrigenda issued since publicationDate Text affectedBRITISH STANDARDBS EN ISO 18369-2:2017EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE N
5、ORMEN ISO 18369-2September 2017ICS 01.040.11; 11.040.70 Supersedes EN ISO 18369-2:2012EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGCEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2017 CEN Ref. No. EN ISO 18369-2:2017: EAll rights
6、of exploitation in any form and by any means reserved worldwide for CEN national MembersOphthalmic optics Contact lenses Part 2: Tolerances (ISO 18369-2:2017)Optique ophtalmique Lentilles de contact Partie 2: Tolrances (ISO 18369-2:2017)Augenoptik Kontaktlinsen Teil 2: Grenzabweichungen (ISO 18369-2
7、2017)This European Standard was approved by CEN on 1 July 2017.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical re
8、ferences concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a C
9、EN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions.CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedoni
10、a, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom.English VersionEN ISO 18369-2:2017 (E)European forewordThis document (
11、EN ISO 18369-2:2017) has been prepared by Technical Committee ISO/TC 172 “Optics and photonics” in collaboration with Technical Committee CEN/TC 170 “Ophthalmic optics” the secretariat of which is held by DIN.This European Standard shall be given the status of a national standard, either by publicat
12、ion of an identical text or by endorsement, at the latest by March 2018, and conflicting national standards shall be withdrawn at the latest by March 2018.Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN shall not be held respo
13、nsible for identifying any or all such patent rights.This document supersedes EN ISO 18369-2:2012.According to the CEN-CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyp
14、rus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and t
15、he United Kingdom.2BS EN ISO 18369-2:2017ISO 18369-2:2017(E)Foreword iv1 Scope . 12 Normative references 13 Terms and definitions . 14 General 14.1 Tolerance limits for contact lenses 14.2 Conformance criteria for testing products . 24.3 Conditioning of contact lenses prior to testing . 24.4 Transmi
16、ttance of ultraviolet radiation . 24.5 Requirements for finish . 24.5.1 Inclusions and surface imperfections 24.5.2 Fenestrations. 24.5.3 Edge contour and finish . 24.6 Additional properties 25 Tolerances for rigid contact lenses 26 Tolerances for soft contact lenses 4Bibliography 7 ISO 2017 All rig
17、hts reserved iiiContents PageBS EN ISO 18369-2:2017ISO 18369-2:2017(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technic
18、al committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely wi
19、th the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed
20、 for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rig
21、hts. ISO shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents).Any trade name used in thi
22、s document is information given for the convenience of users and does not constitute an endorsement.For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the World Tr
23、ade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following URL: www.iso.org/iso/foreword.html.This document was prepared by Technical Committee ISO/TC 172, Optics and photonics, Subcommittee SC 7, Ophthalmic optics and instruments.This third edition cancels and repl
24、aces the second edition (ISO 18369-2:2012), which has been technically revised.A list of all parts in the ISO 18369 series can be found on the ISO website.iv ISO 2017 All rights reservedBS EN ISO 18369-2:2017Ophthalmic optics Contact lenses Part 2: Tolerances (ISO 18369-2:2017)1 ScopeThis document s
25、pecifies the tolerance limits of the principal optical and physical parameters of rigid corneal, rigid scleral and soft contact lenses at the time of manufacture.These tolerances might not apply to other purposes, for example, shelf-life studies.2 Normative referencesThe following documents are refe
26、rred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.ISO 18369-1, Ophthalmic optics
27、 Contact lenses Part 1: Vocabulary, classification systems and recommendations for labelling specificationsISO 18369-3:2017, Ophthalmic optics Contact lenses Part 3: Measurement methodsISO 18369-4:2017, Ophthalmic optics Contact lenses Part 4: Physicochemical properties of contact lens materials3 Te
28、rms and definitionsFor the purposes of this document, the terms and definitions given in ISO 18369-1 apply.ISO and IEC maintain terminological databases for use in standardization at the following addresses: IEC Electropedia: available at http:/www.electropedia.org/ ISO Online browsing platform: ava
29、ilable at http:/www.iso.org/obp 4 General4.1 Tolerance limits for contact lensesWhen tested as described in ISO 18369-3, the dimensional and optical properties for contact lenses shall be as specified within the appropriate tolerance limits given in Table 1, Table 2 and Table 3.When tested as descri
30、bed in ISO 18369-4, the material properties for contact lenses shall be as specified, within the appropriate tolerance limits given in Table 4.INTERNATIONAL STANDARD ISO 18369-2:2017(E) ISO 2017 All rights reserved 1BS EN ISO 18369-2:2017ISO 18369-2:2017(E)4.2 Conformance criteria for testing produc
31、tsThere are three meaningful methods to determine the conformance of contact lens parameters to specified tolerances:a) 100 % inspection a method to determine conformance to a specified value, including tolerances based on evaluation of each item in the population to be evaluated;b) acceptance sampl
32、ing a method to assign a product to a specified conformance level (e.g. acceptance quality limit and limiting quality);c) statistical estimation of performance process assessment where a representative sample is determined and used to estimate performance.Conformance can be based on supplier data fo
33、r lens lots supplied or third-party audits.4.3 Conditioning of contact lenses prior to testingContact lenses shall be equilibrated in standard saline or packaging solution, unless otherwise specified in the relevant test method specified in ISO 18369-3 or ISO 18369-4.4.4 Transmittance of ultraviolet
34、 radiationFor contact lenses claimed to attenuate ultraviolet radiation, total transmittance of ultraviolet radiation through the contact lens shall conform to those amounts specified in Table 4. Such lenses shall be categorized as “Class 1” or “Class 2” absorbers, according to the measured ultravio
35、let radiation transmittance.4.5 Requirements for finish4.5.1 Inclusions and surface imperfectionsWhen examined as specified in ISO 18369-3, the contact lens shall not exhibit any inclusions or surface imperfections which could interfere with its intended functional use.4.5.2 FenestrationsThe front a
36、nd back edges of the holes shall appear finished in the style specified by the manufacturer when examined under a minimum of 7 magnification.4.5.3 Edge contour and finishWhen examined under a minimum of 7 magnification, the contact lens edge shall meet the quality characteristics described by the ma
37、nufacturer with respect to shape, smoothness and polish.4.6 Additional propertiesWhen a manufacturer claims additional contact lens properties (e.g. aspherical design), the properties shall be described by the manufacturer, together with appropriate measurement methods and tolerances.5 Tolerances fo
38、r rigid contact lensesWhen tested as described in ISO 18369-3, the dimensional and optical properties of corneal and scleral rigid contact lenses shall be as specified within the appropriate tolerance limits given in Table 1 and Table 2.2 ISO 2017 All rights reservedBS EN ISO 18369-2:2017ISO 18369-2
39、2017(E)For fenestration, truncation and displacement, measured values shall not differ from the specified values by more than 10 %.Table 1 Dimensional tolerances for rigid contact lensesDimensions in millimetresPropertyTolerance limitRelevant methodCorneal contact lensScleral contact lensPMMA Gas p
40、ermeableBack optic zone radius 0,025 0,05 0,10 ISO 18369-3:2017, 4.2Back optic zone radii of toroidal surfacesa,bISO 18369-3:2017, 4.2where 0 0,60,0250,0350,0550,0750,050,060,070,090,120,130,150,17Back optic zone diameterc0,20 0,20 0,20 ISO 18369-3:2017, 4.4Back scleral radius (of preformed lens) 0,
41、10 ISO 18369-3:2017, 4.2Basic or primary optic diameter 0,20 ISO 18369-3:2017, 4.4Back or front peripheral radius (where measurable)c0,10 0,10 0,10 ISO 18369-3:2017, 4.2Back peripheral diameterc0,20 0,200,20 (for preformed lenses)ISO 18369-3:2017, 4.4Tot al diameterb0,10 0,10 0,25 ISO 18369-3:2017,
42、4.4Front optic zone diameterc0,20 0,20 0,20 ISO 18369-3:2017, 4.4Bifocal segment height 0,10 to +0,20 0,10 to +0,20 0,10 to +0,20 ISO 18369-3:2017, 4.4Centre thickness 0,02 0,02 0,10 ISO 18369-3:2017, 4.5ar is the difference between the radii of the two principal meridians.bThe tolerance applies to
43、each meridian.cThese tolerances apply only to contact lenses with spherical surfaces and distinct curves; they are for a finished contact lens and there is a possibility that any blending makes measurement difficult. ISO 2017 All rights reserved 3BS EN ISO 18369-2:2017ISO 18369-2:2017(E)Table 2 Opti
44、cal tolerances for rigid contact lensesDimension Tolerance limit Relevant methodLabel back vertex power (FL) in the weaker merid-ian|FL| 5,00 D5,00 D 20,00 D0,12 D0,18 D0,25 D0,37 D0,50 DISO 18369-3:2017, 4.3Optical centration for scleral lenses only (maximum error)0,50 mm ISO 18369-3:2017, 4.4Cylin
45、der powerto 2,00 Dover 2,00 D to 4,00 Dover 4,00 D0,25 D0,37 D0,50 DISO 18369-3:2017, 4.3Cylinder axis 5 ISO 18369-3:2017, 4.36 Tolerances for soft contact lensesContact lenses shall be equilibrated in standard saline or packaging solution unless otherwise stated in the relevant test method specifie
46、d in ISO 18369-3 or ISO 18369-4.The results for any test shall include information concerning the solution used (standard saline or packaging solution).Where a manufacturer is unable to comply with one or more requirements specified in this document, a deviation from this document is permitted provi
47、ded that there are clinical data (see ISO 11980) and that a risk assessment (see ISO 14971) has been carried out to support the products safety and performance.This proviso only applies to stock soft lenses when justified and validated by statements from the manufacturer. It does not apply to custom
48、 specified lenses.A manufacturer may have a lens design including specified tolerances which may differ from those in this document. As part of the design file, the manufacturer will have clinical data and will have carried out a risk assessment.4 ISO 2017 All rights reservedBS EN ISO 18369-2:2017IS
49、O 18369-2:2017(E)Table 3 Parameter tolerances for soft contact lensesDimension Tolerance limits Relevant methodBack optic zone radius/equivalent posterior radius of curvature/base curve equivalent0,20 mm ISO 18369-3:2017, 4.2Sagitta 0,05 mmaISO 18369-3:2017, 4.2Tot al diameter 0,20 mm ISO 18369-3:2017, 4.4Centre thickness, tC bISO 18369-3:2017, 4.5 tC 0,10 mmt C 0,10 mm(0,010 mm + 0,10 tC)(0,015 mm + 0,05 t C)Label back vertex power (FL)ISO 1836
