BS EN ISO 8321-2:2000 pdf – Ophthalmic optics Ð Specifications for material, optical and dimensional properties ofcontact lenses Ð Part 2: Single-vision hydrogel contact lenses

BS EN ISO 8321-2:2000 pdf – Ophthalmic optics Ð Specifications for material, optical and dimensional properties ofcontact lenses Ð Part 2: Single-vision hydrogel contact lenses.
1? Scope This part of ISO 8321 specifies requirements for hydrated single-vision hydrogel contact lenses including tolerance limits for material, optical and dimensional properties. A method for presenting the specification of contact lenses is described in annex A. 2? Normative references The following normative documents contain provisions which, through reference in this text, constitute provisions of this part of ISO 8321 . 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 8321 are encouraged to investigate the possibility of 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 :— 1 ? , Contact lenses and contact lens care products — Vocabulary — Part 1 : Contact lense s. ISO 8599:1 994, Optics and optical instruments — Contact lenses — Determination of the spectral and luminous transmittance . ISO 9337-1 :1 999, Contact lenses — Determination of back vertex power — Part 1 : Method using focimeter with manual focusing . ISO 9338:1 996, Optics and optical instruments — Contact lenses — Determination of the diameter s. ISO 9339-2:1 998, Optics and optical instruments — Contact lenses — Determination of thickness — Part 2: Hydrogel contact lenses . ISO 991 3-1 :1 996, Optics and optical instruments — Contact lenses — Part 1 : Determination of oxygen permeability and transmissibility with the FATT method . ISO 991 4:1 995, Optics and optical instruments — Contact lenses — Determination of refractive index of contact lens materials . ISO 1 0338:1 996, Optics and optical instruments — Contact lenses — Determination of curvature . ISO 1 0339:1 997, Ophthalmic optics — Contact lenses — Determination of water content of hydrogel lenses .
3? Terms and definitions For the purposes of this part of ISO 8321 , the terms and definitions given in ISO 8320-1 apply. 4? Requirements for dimensions and optical properties 4.1? Test methods Each dimension and physical or optical property specified shall be determined using a test method with a measurement tolerance limit better than one-half of the tolerance limit specified for the property. The International Standards which specify the relevant test methods are listed in Tables 1 and 2. 4.2? Conditioning of contact lenses prior to testing Contact lenses shall be conditioned in accordance with the relevant test method. 4.3? Tolerances When tested as described in 4.1 and 4.2 the dimensional and optical properties shall be as specified, within the appropriate tolerance limits given in Table 1 and the material physical properties as given in Table 2. 5? Requirement for finish 5.1? Criteria Acceptance and failure criteria for inclusions, surface imperfections, edge contour and finish shall be documented by the manufacturer. 5.2? Inclusions and surface finish When examined at ?1 0 magnification in standard saline solution according to ISO 1 0344, the contact lens shall not exhibit any inclusions or surface imperfections which could interfere with its intended functional use. 5.3? Edge contour and finish When examined at ?7 magnification, the contact lens edge shall meet the quality characteristics indicated by the manufacturer with respect to shape, smoothness and polish.