ICS 11.040.70                          MHD 05

(Superseding IS 14323 : 1996)

Reaffirmed 2017

NATIONAL FOREWORD

This Indian Standard (Part 2) which is identical with ISO 11979-2 : 1999 ‘Ophthalmic implants - Intraocular lenses - Part 2: Optical properties and test methods’ issued by the International Organization for Standardization (ISO) was adopted by the Bureau of Indian Standards on the recommendation of the Ophthalmic Instruments and Appliances Sectional Committee and approval of the Medical Equipment and Hospital Planning Division Council.

This standard is published in ten parts. The other parts of this series are:

Part 1 Vocabulary

Part 3 Mechanical properties and test methods

Part 4 Labelling and information

Part 5 Biocompatibility

Part 6 Shelf-life and transport stability

Part 7 Clinical investigations

Part 8 Fundamental requirements

Part 9 Multifocal intraocular lenses

Part 10 Phakic intraocular lenses

The IS/ISO 11979 series will supersede IS 14323 : 1996 ‘Intraocular lenses - Specification’ and after the publication of this series of standards IS 14323 shall be treated as withdrawn.

This standard contains several test methods for which associated requirements are given and one test method for which no requirement is formulated. The former are directly connected to the optical functions of intraocular lenses. The latter, the test for spectral transmittance, has been provided for those interested in information about UV transmission and in specific situations, for example, when using laser light sources for medical diagnosis and treatment.

Extensive interlaboratory testing has been carried out before setting the limits specified.

The accuracy in the determination of dioptric power has an error that is not negligible in relation to the halfdioptre steps in which intraocular lenses are commonly labelled. The dioptric power tolerances take this fact into account. Hence the limits set may lead to some overlap into the next labelled power, especially for high dioptre lenses. Reference [1] gives further discussion on this subject.