1、BRITISH STANDARDBS EN ISO 18369-3:2006Ophthalmic optics Contact lenses Part 3: Measurement methodsThe European Standard EN ISO 18369-3:2006 has the status of a British StandardICS 11.040.70g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g5
2、1g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS EN ISO 18369-3:2006This British Standard was published under the authority of the Standards Policy and Strategy Committee on 29 September 2006 BSI 2006ISBN 0 580 49251 6National forewordThis British Standard
3、was published by BSI. It is the UK implementation of EN ISO 18369-3:2006. It supersedes BS EN ISO 10338:1998, BS EN ISO 10344:1998, BS EN ISO 8599:1997, BS EN ISO 9337-1:2001, BS EN ISO 9337-2:2004, BS EN ISO 9338:1998, BS EN ISO 9339-1:1998, BS EN ISO 9339-2:1998 and BS EN ISO 9341:1998, which are
4、withdrawn.The UK participation in its preparation was entrusted by Technical Committee CH/172, Ophthalmic optics, to Subcommittee CH/172/9, Contact lenses and contact lens care products.A list of organizations represented on CH/172/9 can be obtained on request to its secretary.This publication does
5、not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations. Amendments issued since publicationAmd. No. Date CommentsEUROPEAN STANDARDNORME EUROPENNEEUROPISCHE N
6、ORMEN ISO 18369-3August 2006ICS 11.040.70 Supersedes EN ISO 10338:1997, EN ISO 10344:1998,EN ISO 8599:1996, EN ISO 9337-1:2000, EN ISO 9337-2:2004, EN ISO 9338:1998, EN ISO 9339-1:1998, EN ISO9339-2:1998, EN ISO 9339-2:1998English VersionOphthalmic optics - Contact lenses - Part 3: Measurementmethod
7、s (ISO 18369-3:2006)Optique ophtalmique - Lentilles de contact - Partie 3:Mthodes de mesure (ISO 18369-3:2006)Augenoptik - Kontaktlinsen - Teil 3: Messverfahren (ISO18369-3:2006)This European Standard was approved by CEN on 24 May 2006.CEN members are bound to comply with the CEN/CENELEC Internal Re
8、gulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the Central Secretariat or to any CEN member.This Eu
9、ropean Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the officialversions.CEN members are the natio
10、nal standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania,Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdo
11、m.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2006 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN ISO 18369-3:2006: EForewo
12、rd This document (EN ISO 18369-3:2006) has been prepared by Technical Committee ISO/TC 172 “Optics and optical instruments“ 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 nationa
13、l standard, either by publication of an identical text or by endorsement, at the latest by February 2007, and conflicting national standards shall be withdrawn at the latest by February 2007. This document supersedes EN ISO 10338:1997, EN ISO 10344:1998, EN ISO 8599:1996, EN ISO 9337-1:2000, EN ISO
14、9337-2:2004, EN ISO 9338:1998, EN ISO 9339-1:1998, EN ISO 9339-2:1998, EN ISO 9339-2:1998. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denma
15、rk, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. Endorsement notice The text of ISO 18369-3:2006 has been approved
16、by CEN as EN ISO 18369-3:2006 without any modifications. EN ISO 18369-3:2006Reference numberISO 18369-3:2006(E)INTERNATIONAL STANDARD ISO18369-3First edition2006-08-15Ophthalmic optics Contact lenses Part 3: Measurement methods Optique ophtalmique Lentilles de contact Partie 3: Mthodes de mesure EN
17、ISO 18369-3:2006ii iiiContents Page Foreword iv Introduction v 1 Scope . 1 2 Normative references . 1 3 Terms and definitions. 1 4 Methods of measurement for contact lenses 1 4.1 Radius of curvature 1 4.2 Back vertex power 14 4.3 Diameters and widths. 16 4.4 Thickness 22 4.5 Inspection of edges, inc
18、lusions and surface imperfections 24 4.6 Determination of spectral and luminous transmittance . 26 4.7 Saline solution for contact lens testing 28 5 Test report . 30 Annex A (informative) Measurement of rigid contact lens curvature using interferometry. 31 Annex B (informative) Determination of back
19、 vertex power of soft contact lenses immersed in saline using the Moir deflectometer or Hartmann methods. 33 Bibliography . 37 EN ISO 18369-3:2006iv Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work
20、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 to be represented on that committee. International organizations, governmental and non-government
21、al, 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. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The mai
22、n task of technical committees is to prepare International Standards. Draft International 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. Att
23、ention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 18369-3 was prepared by Technical Committee ISO/TC 172, Optics and photonics, Subcommittee SC 7, Oph
24、thalmic optics and instruments. This first edition cancels and replaces ISO 8599:1994, ISO 9337-1:1999, ISO 9337-2:2004, ISO 9338:1996, ISO 9339-1:1996, ISO 9339-2:1998, ISO 9341:1996, ISO 10338:1996 and ISO 10344:1996, which have been technically revised. ISO 18369 consists of the following parts,
25、under the general title Ophthalmic optics Contact lenses: Part 1: Vocabulary, classification system and recommendations for labelling specifications Part 2: Tolerances Part 3: Measurement methods Part 4: Physicochemical properties of contact lens materials EN ISO 18369-3:2006vIntroduction The ISO 18
26、369 series applies to contact lenses, which are devices worn over the front surface of the eye in contact with the preocular tear film. This part of ISO 18369 covers rigid (hard) corneal and scleral contact lenses, as well as soft contact lenses. Rigid lenses maintain their own shape unsupported and
27、 are made of transparent optical-grade plastics, such as polymethylmethacrylate (PMMA), cellulose acetate butyrate (CAB), polyacrylate/siloxane copolymers, rigid polysiloxanes (silicone resins), butylstyrenes, fluoropolymers, and fluorosiloxanes, etc. Soft contact lenses are easily deformable and re
28、quire support for proper shape. A very large subset of soft contact lenses consists of transparent hydrogels containing water in concentrations greater than 10 %. Soft contact lenses can also be made of non-hydrogel materials, e.g. flexible polysiloxanes (silicone elastomers). The ISO 18369 series i
29、s applicable to determining allowable tolerances of parameters and properties important for proper functioning of contact lenses as optical devices. The ISO 18369 includes tolerances for single-vision contact lenses, bifocal lenses, lenses that alter the flux density and/or spectral composition of t
30、ransmitted visible light (tinted or pigmented contact lenses, such as those with enhancing, handling, and/or opaque tints), and lenses that significantly attenuate ultraviolet radiation (UV-absorbing lenses). The ISO 18369 series of standards covers contact lenses designed with spherical, toric, and
31、 aspheric surfaces, and recommended methods for the specification of contact lenses. EN ISO 18369-3:2006blank1Ophthalmic optics Contact lenses Part 3: Measurement methods 1 Scope This part of ISO 18369 specifies the methods for measuring the physical and optical properties of contact lenses specifie
32、d in ISO 18369-2, i.e. radius of curvature, back vertex power, diameter, thickness, inspection of edges, inclusions and surface imperfections, and determination of spectral and luminous transmittances. This part of ISO 18369 also specifies the equilibrating solution, standard saline solution, for te
33、sting of contact lenses. 2 Normative references The following referenced documents are indispensable for the application 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. I
34、SO 3696:1987, Water for analytical laboratory use Specification and test methods ISO 18369-1, Ophthalmic optics Contact lenses Part 1: Vocabulary, classification system and recommendations for labelling specifications 3 Terms and definitions For the purposes of this document, the terms and definitio
35、ns given in ISO 18369-1 apply. 4 Methods of measurement for contact lenses 4.1 Radius of curvature 4.1.1 General There are two generally accepted instruments for determining the radius of curvature of rigid contact lens surfaces. These are the optical microspherometer (see 4.1.2) and the ophthalmome
36、ter with contact lens attachment (see 4.1.3). The ophthalmometer method (see 4.1.3) measures the reflected image size of a target placed a known distance in front of a rigid or soft lens surface, and the relationship between curvature and magnification of the reflected image is then used to determin
37、e the back optic zone radius. Ultrasonic, mechanical, and optical measurements of sagittal depth are applicable to hydrogel contact lens surfaces as indicated in 4.1.4 and Table 1, but are generally not recommended instead of radius EN ISO 18369-3:20062 measurement for rigid spherical surfaces becau
38、se aberration, toricity and other errors are masked during measurement. Sagittal depth of rigid aspheric surfaces can be useful, however, as indicated in 4.1.2.4. In addition to these three measurement methods, a method using interferometry and applicable to rigid contact lenses is given in Annex A
39、for information. Table 1 Test methods, application and reproducibility Subclause Test method/application Reproducibility a, bR 4.1.2 Optical microspherometry Spherical rigid lenses 0,015 mm in air 4.1.3 Ophthalmometry Spherical rigid lenses Spherical rigid lenses Spherical hydrogel lenses (38 % wate
40、r content, tC 0,1 mm) 0,015 mm in air 0,025 mm in saline solution 0,050 mm in saline solution 4.1.4 Sagittal height method Hydrogel lenses (38 % water content, tC 0,1 mm) Hydrogel lenses (55 % water content, tC 0,1 mm) Hydrogel lenses (70 % water content, tC 0,1 mm) 0,050 mm in saline solution 0,100
41、 mm in saline solution 0,200 mm in saline solution NOTE This table provides reproducibility values for spherical rigid lenses, because this type of lenses was included in the ring test carried out. However, in general the values equally apply to aspherical and toric rigid lenses.aThe reproducibility
42、 of any method should be half or less of the product tolerance specified in ISO 18369-2 in order to verify the tolerance. bReproducibility, R, as defined in ISO 5725-11. 4.1.2 Microspherometer 4.1.2.1 Principle The microspherometer locates the surface vertex and the aerial image (centre of curvature
43、) with the Drysdale principle, as described below. The distance between these two points is the radius of curvature for a spherical surface, and is known as the apical radius of curvature for an aspheric surface derived from a conic section. The microspherometer can be used to measure radii of the t
44、wo primary meridians of a rigid toric surface, and with a special tilting attachment, eccentric radii can be measured as found in the toric periphery of a rigid aspheric surface. When the posterior surface is measured, the back optic zone radius is that which is verified. The optical microspheromete
45、r consists essentially of a microscope fitted with a vertical illuminator. Light from the target T (Figure 1) is reflected down the microscope tube by the semi-silvered mirror M and passes through the microscope objective to form an image of the target at T. If the focus coincides with the lens surf
46、ace, then light is reflected back along the diametrically opposite path to form images at T and T. The image at T coincides with the first principle focus of the eyepiece when a sharp image is seen by the observer Figure 1 a). This is referred to as the “surface image”. The distance between the micr
47、oscope and the lens surface is increased by either raising the microscope or lowering the lens on the microscope stage until the image (T) formed by the objective coincides with C (the centre of curvature of the surface). Light from the target T strikes the lens surface normally and is reflected bac
48、k along its own path to form images at T and T as before Figure 1 b). A sharp image of the target is again seen by the observer. This is referred to as the “aerial image”. The distance through which the EN ISO 18369-3:20063microscope or stage has been moved is equal to the radius (r) of curvature of
49、 the surface. The distance of travel is measured with an analogue or digital distance gauge incorporated in the instrument. In the case of a toric test surface, there is a radius of curvature determined in each of two primary meridians aligned with lines within the illuminated microspherometer target. It is also possible to measure the front surface radius of curvature by orienting the lens such that its front surface is presented to the microscope. In this instance, the aerial image is below the lens, such that the microscope
