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1、BRITISH STANDARD BS EN ISO 9337-1:2001 Incorporating Amendment No. 1 to BS ISO 9337-1:1999 (renumbers the BS ISO as BS EN ISO 9337-1:2001) Contact lenses Determination of back vertex power Part 1: Method using focimeter with manual focusing The European Standard EN ISO 9337-1:2000 has the status of
2、a British Standard ICS 11.040.70 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 17 09:52:20 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN ISO 9337-1:2001 This British Standard, having been prepared under the direction of
3、the Health and Environment Sector Committee, was published under the authority of the Standards Committee and comes into effect on 15 July 1999 BSI 07-2001 ISBN 0 580 32773 6 National foreword This British Standard is the official English language version of EN ISO 9337-1:2000. It is identical with
4、ISO 9337-1:1999. The UK participation in its preparation was entrusted by Technical Committee CH/78, Ophthalmic optics, to Subcommittee CH/78/4, Physical properties of contact lenses, which has the responsibility to: aid enquirers to understand the text; present to the responsible international/Euro
5、pean committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this subcommittee can be obtained on request to its secretary
6、. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Ele
7、ctronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract, Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This
8、document comprises a front cover, an inside front cover, the EN ISO title page, the EN ISO foreword page, the ISO title page, pages ii to iv, pages 1 to 7 and a back cover. The BSI copyright notice displayed is this document indicates when the document was last issued. Amendments issued since public
9、ation Amd. No.DateComments 13236July 2001Implementation of the European Standard Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 17 09:52:20 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 9337-1 May 2000 ICS 11.040.70 English version Contact l
10、enses Determination of back vertex power Part 1: Method using focimeter with manual focusing (ISO 9337-1:1999) Lentilles de contact Dtermination de la puissance frontale arrire Partie 1: Mthode utilisant un frontofocomtre mise au point manuelle (ISO 9337-1:1999) Kontaktlinsen Bestimmung des bildseit
11、igen Scheitelbrechwertes Teil 1: Verfahren unter Verwendung eines manuell einzustellenden Scheitelbrechwert Messgertes (ISO 9337-1:1999) This European Standard was approved by CEN on 17 April 2000. CEN members are bound to comply with the CEN/CENELEC Internal regulations which stipulate the conditio
12、ns for giving this European Standard the staus of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CEN member. This European Standard exists in three offi
13、cial version (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, B
14、elgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secre
15、tariat: rue de Stassart 36, B-1050 Brussels 2000 CENAll rights of exploitation in any form and by any means reserved worldwide for CEN national Members Ref. No. EN ISO 9337-1:2000 E Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 17 09:52:20 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN ISO 9337
16、-1:2000 BSI 07-2001 ii Foreword The text of the International Standard from Technical Committee ISO/TC 172, Optics and optical instruments, of the International Organization for Standardization (ISO) has been taken over as a European Standard by Technical Committee CEN/TC 170, Ophthalmic optics, the
17、 Secretariat of which is held by DIN. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by November 2000, and conflicting national standards shall be withdrawn at the latest by November 2000. According
18、 to CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain,
19、 Sweden, Switzerland and the United Kingdom. NOTENormative references to International Standards are listed in Annex ZA (normative). A-deviations are given in Annex ZB (informative). Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 17 09:52:20 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Licensed C
20、opy: sheffieldun sheffieldun, na, Fri Nov 17 09:52:20 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN ISO 9337-1:2000 ii BSI 07-2001 Contents Page Forewordiii Introduction1 1Scope1 2Normative references1 3Terms and definitions1 4Determination of back vertex power2 4.1Principle2 4.2Apparatus and reagen
21、t2 4.3Conditioning of lenses prior to testing2 4.4Procedure3 4.4.1Calibration3 4.4.2Measurement of back vertex power of rigid contact lenses3 4.4.3Measurement of back vertex power of hydrogel contact lenses3 5Expression of results4 6Precision data4 7Test report4 Annex A (informative) Precision data5
22、 Bibliography 6 Figure 1 Example of a contact lens support in comparison with the spectacle lens support which it replaces4 Table A.1 Precision data for rigid contact lenses5 Table A.2 Precision data for spherical hydrogel contact lenses5 Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 17 09:52:
23、20 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN ISO 9337-1:2000 BSI 07-2001iii Foreword ISO (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
24、ISO technical 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
25、 closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3. Draft International Standards adopted by the technical committees are circul
26、ated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. International Standard ISO 9337-1 was prepared by ISO/TC 172, Optics and optical instruments, Subcommittee SC 7, Ophthalmic optics and instruments. I
27、SO 9337 consists of the following parts, under the general title Contact lenses Determination of back vertex power: Part 1: Method using focimeter with manual focusing; Part 2: Measurement on contact lenses immersed in saline. Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 17 09:52:20 GMT+00:00
28、 2006, Uncontrolled Copy, (c) BSI iv blank Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 17 09:52:20 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN ISO 9337-1:2000 BSI 07-2001 1 Introduction It is intended that the test methods described in this part of ISO 9337 be used by contact lens manufact
29、urers, practitioners and other interested parties. The method as applied to rigid contact lenses does not differentiate between contact lenses which are stored wet and those which are stored dry. The test procedure allows for wet storage by specifying that wet contact lenses require blotting before
30、measurement. It is considered that the measured value of back vertex power of rigid contact lenses is not influenced by wet storage. It has been assumed in drafting this part of ISO 9337 that the execution of its provisions will be entrusted to appropriately qualified and experienced people. 1 Scope
31、 This part of ISO 9337 describes test methods for the determination of back vertex power of both rigid and hydrogel contact lenses in air using a focimeter with manual focusing. It is applicable to finished contact lenses. 2 Normative references The following normative documents contain provisions w
32、hich, through reference in this text, constitute provisions of this part of ISO 9337. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this part of ISO 9337 are encouraged to investigate the possibility o
33、f applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain registers of currently valid International Standards. ISO 8320-1, Contact lenses and contact lens
34、care products Vocabulary Part 1: Contact lenses. ISO 10344, Ophthalmic optics Contact lenses Saline solution for contact lens testing. 3 Terms and definitions For the purposes of this part of ISO 9337, the terms and definitions given in ISO 8320-1 apply, together with the following. 3.1 back vertex
35、power F?v reciprocal of the paraxial value of the back vertex focal length, measured in metres 3.2 dioptre D unit of focusing power of a lens or surface, or of the vergence (refractive index divided by the radius) of a wavefront NOTE 1Commonly used symbols for dioptre are D, dpt and ?. NOTE 2Dioptre
36、 is expressed in reciprocal metres (m1). 3.3 repeatability closeness of agreement between mutually independent test results obtained under repeatability conditions ISO 3534-1 3.4 repeatability conditions conditions where mutually independent test results are obtained with the same method on identica
37、l test material in the same laboratory by the same operator using the same equipment within short intervals of time ISO 3534-1 Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 17 09:52:20 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN ISO 9337-1:2000 2 BSI 07-2001 3.5 repeatability value r value b
38、elow which the absolute difference between two single test results obtained under repeatability conditions may be expected to lie with a probability of 95 % ISO 3534-1 3.6 reproducibility closeness of agreement between mutually independent test results obtained under reproducibility conditions ISO 3
39、534-1 3.7 reproducibility conditions conditions where mutually independent test results are obtained with the same methods on identical test material in different laboratories with different operators using different equipment ISO 3534-1 3.8 reproducibility value R value below which the absolute dif
40、ference between two single test results obtained under reproducibility conditions may be expected to lie with a probability of 95 % ISO 3534-1 4 Determination of back vertex power 4.1 Principle The back vertex power of rigid and hydrogel contact lenses in air is measured using the focimeter. 4.2 App
41、aratus and reagent 4.2.1 Focimeter, provided with a contact lens support. NOTE 1Manually focusing focimeters conforming to ISO 8598 may be used. Other focimeters may be used provided that the readings derived are shown to be equivalent to those of a manually focusing focimeter. The contact lens supp
42、ort shall be designed so that the contact lens rests on the supporting ring only. Figure 1 shows an example of a suitable support design. Its central aperture has a diameter of 4,50 mm?0,50 mm and projects 0,55 mm?0,02 mm less than the spectacle lens support which it re- places. NOTE 2This change in
43、 projection provides accurate power readings on lenses with a back optic zone radius of 8,00 mm. Lenses with back optic zone radii substantially different from this may require further vertex distance correction. 4.2.2 Six spherical test lenses having nominal back vertex power within one dioptre of
44、?20,00 D, ?15,00 D, ?10,00 D, ?5,00 D, +5,00 D, +10,00 D, +15,00 D and +20,00 D respectively. The back vertex powers of the test lenses shall be traceable to a national or International Standard. NOTETest lenses conforming to ISO 9342 may be used. 4.2.3 Standard saline solution conforming to ISO 103
45、44. 4.3 Conditioning of contact lenses prior to testing Condition each contact lens prior to testing as follows. a) For rigid contact lenses, maintain at a temperature of 20?C?5?C for 30 min. b) For hydrogel contact lenses, immerse in a vial filled with standard saline solution (4.2.3) and maintain
46、at a temperature of 20,0?C 0,5?C for 30 min. NOTEIf 30 min is not sufficient time for the contact lens polymer to equilibrate, the manufacturer should state the time required. Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 17 09:52:20 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN ISO 9337-1:200
47、0 BSI 07-2001 3 4.4 Procedure 4.4.1 Calibration At a temperature of 20?C?5?C and using the spherical test lenses (4.2.2), calibrate the focimeter fitted with its spectacle lens support. Place each test lens centrally with its back surface against the spectacle lens support, and focus the focimeter t
48、o obtain the clearest possible image. Record the focimeter reading. Take three independent readings within 30 s and record the mean. Plot the results on a calibration curve. NOTE 1The term “independent” means that the test lens is removed from the instrument and remounted between each reading. NOTE
49、2The preferred method of plotting a calibration curve is to use a quadratic best-fit. 4.4.2 Measurement of back vertex power of rigid contact lenses If necessary, blot the contact lens between two layers of tissue to remove all visible surface liquid. Place the lens with its back surface centrally on the contact lens support and focus the focimeter to obtain the clearest possible image. Record the focimeter reading. NOTEBefore measuring back vertex power, t