1、BRITISH STANDARD BS EN ISO 11985:1998 Ophthalmic optics Contact lenses Ageing by exposure to UV and visible radiation (invitromethod) The European Standard EN ISO 11985:1997 has the status of a British Standard ICS 11.040.70BSEN ISO 11985:1998 This British Standard, having been prepared under the di
2、rectionof the Health and Environment Sector Board, waspublished under the authorityof the Standards Boardand comes into effect on 15April 1998 BSI 04-1999 ISBN 0 580 29381 5 National foreword This British Standard is the English language version of EN ISO11985:1997. It is identical with ISO11985:199
3、7. 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/European committee
4、 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. Cross-refere
5、nces Attention is drawn to the fact that CEN and CENELEC standards normally include an annex which lists normative references to international publications with their corresponding European publications. The British Standards which implement these international or European publications may be found
6、in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards a
7、re responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, theEN ISO title page, page 2, the ISO title page, page ii, pages
8、1 to 7 and abackcover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Amendments issued since publication Amd. No. Date CommentsBSEN ISO 11985:1998 BSI 04-1999 i Contents Page Nati
9、onal foreword Inside front cover Foreword 2 Foreword ii Text of ISO 11985 1ii blankEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 11985 December 1997 ICS 11.040.70 Descriptors: See ISO document English version Ophthalmic optics Contact lenses Ageing by exposure to UV and visible radiation
10、(in vitro method) (ISO11985:1997) Optique ophtalmique Lentilles de contact Vieillissement des lentilles de contact par exposition aux rayonnements UV et visible (mthode in vitro) (ISO11985:1997) Augenoptik Kontaktlinsen Alterung durch Einwirkung von ultravioletter und sichtbarer Strahlung (in vitro-
11、Verfahren) (ISO 11985:1997) This European Standard was approved by CEN on 4 December 1997. 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 l
12、ists 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 official versions (English, French, German). A version in any other language made by translation under the res
13、ponsibility 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, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, N
14、etherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1997 CEN All rights of exploitation in any form and by any me
15、ans reserved worldwide for CEN national Members. Ref. No. EN ISO 11985:1997 EEN ISO 11985:1997 BSI 04-1999 2 Foreword The text of the International Standard ISO11985:1997 has been prepared by Technical Committee ISO/TC 172 “Optics and optical instruments” in collaboration with Technical Committee CE
16、N/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 publication of an identical text or by endorsement, at the latest by June 1998, and conflicting national standards shall be withdrawn at the lates
17、t by June 1998. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, CzechRepublic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlan
18、ds, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The text of the International Standard ISO11985:1997 was approved by CEN as a European Standard without any modification. Contents Page Foreword 2 1 Scope 1 2 Normative reference 1 3 Principle 1 4 Apparatus 1
19、 5 Samples 7 6 Procedure 7 7 Test report 7 Figure 1 Energy distribution 2 Figure 2 IR filter transmittance 3 Figure 3 UV domain of xenon lamp 4 Figure 4 Radiation source and apparatus 5 Figure 5 Cuvette assembly 6EN ISO 11985:1997 ii BSI 04-1999 Foreword ISO (the International Organization for Stand
20、ardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right
21、to be represented on that committee. International organisations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. Draft Internatio
22、nal Standards adopted by the technical committees are circulated 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 ISO11985 was prepared by ISO/TC 172 Optics and optical instruments
23、, Subcommittee SC 7, Ophthalmic optics and instruments. Descriptors: Optics, optical equipment, ophthalmic equipment, contact lenses, ageing (materials), ageing tests (materials), artificial light tests, solar radiation, ultraviolet radiation.EN ISO 11985:1997 BSI 04-1999 1 1 Scope This Internationa
24、l Standard describes an in vitro method which simulates the ageing of rigid (hard) and soft lenses in daylight. The existence of this International Standard does not imply in any way that the testing of contact lenses for ageing by ultraviolet (UV) and visible radiation is a requirement. 2 Normative
25、 reference The following standard contains provisions which, through reference in this text, constitute provisions of this International Standard. At the time of the publication, the edition indicated was valid. All standards are subject to revision, and parties to agreements based on this Internati
26、onal Standard are encouraged to investigate the possibility of applying the most recent edition of the standard indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO 10344:1996, Optics and optical instruments Contact lenses Saline solution for con
27、tact lens testing. 3 Principle One aspect of the ageing of contact lenses in normal use is simulated by exposure to an intense source of light. 4 Apparatus 4.1 High pressure xenon lamp, with a quartz envelope and with filters giving a spectral distribution corresponding to that of solar radiation. N
28、OTE 1An example of such a lamp is shown in Figure 1. NOTE 2High intensity UV sources present radiation hazards if not properly shielded and safety hazards if not properly maintained. 4.2 Infrared (IR) filter, with a transmittance of less than 50% of the incident radiation in the range650nm to 850nm.
29、 NOTEAn example of the transmittance of an IR filter is shown in Figure 2. 4.3 Ultraviolet (UV) filter, with a transmittance corresponding to solar radiation. The transmittance shall be 0% below a wavelength of 290nm and greater than 90% between wavelengths of 380nm and 750 nm. NOTEAn example of the
30、 effect of such a UV filter is shown in Figure 3. 4.4 Mirrors, two, capable of reflecting UV and visible radiation. 4.5 Radiation source, comprising a xenon lamp (4.1), IR filter (4.2), UV filter (4.3), mirrors (4.4) and parabolic reflector assembled as shown in Figure 4. 4.6 Cuvette, manufactured f
31、rom quartz and designed to hold contact lens(es). It shall be provided with a silicone rubber seal retained in position using a suitable clamp. When filled with standard saline solution (ISO10344), the cuvette shall not absorb more than 2% of incident radiation between the wavelengths 290 nm and 750
32、 nm. NOTESuch an arrangement retaining two cuvettes is shown in Figure 5.EN ISO 11985:1997 2 BSI 04-1999 Figure 1 Energy distributionEN ISO 11985:1997 BSI 04-1999 3 Figure 2 IR filter transmittanceEN ISO 11985:1997 4 BSI 04-1999 Figure 3 UV domain of xenon lampEN ISO 11985:1997 BSI 04-1999 5 Figure
33、4 Radiation source and apparatusEN ISO 11985:1997 6 BSI 04-1999 Figure 5 Cuvette assemblyEN ISO 11985:1997 BSI 04-1999 7 5 Samples Take the new unused contact lenses from the normal production process. Ensure that no lens has been specially treated or conditioned prior to the test. 6 Procedure 6.1 P
34、lace one sample lens in each cuvette (4.6). Fill the cuvette with the saline solution conforming to ISO10344. Place the silicone rubber seal on the tip of the cuvette. Ensure that there are no air bubbles. Fix the seal in position with the clamp. 6.2 Ensure that the total irradiance between 300 nm a
35、nd 800 nm is 240 W/m 2to 260 W/m 2and that, if more than one lens is exposed simultaneously, each lens is subjected to the same irradiation. Ensure that the irradiation is essentially perpendicular to the surface on which the sample rests. Expose the samples to the light source (see 4.5) at a distan
36、ce of (295 5)mm for h unless otherwise specified by the manufacturer. During the exposure, ensure that the temperature of the saline solution in the cuvette remains below40 C. 7 Test report The test report shall contain at least the following information: a) a reference to this International Standar
37、d, i.e.ISO11985; b) the identification of the contact lens submitted to the procedure; c) the date of submission of the contact lens to the procedure. 20 +1 0 BS EN ISO 11985:1998 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution BSI is the independent national body responsible
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