ISO/WD 21395-1

Optics and photonics — Test method for refractive index of optical glasses — Part 1: Minimum deviation method

General information

Current stage: 20.60 Effective date: Apr 17, 2026

Originator: ISO

Owner: ISO/TC 172/SC 3

Type: International Standard

Scope

This document specifies the measuring method for the refractive index of optical glasses with the accuracy within 1 × 10−5 used in the spectral range from 365 nm to 2 400 nm.
Additional information on how to apply the refractive index in the dispersion and the various dispersion formulae of optical glasses is given in Annex A and Annex B.

Life cycle

PREVIOUSLY

PUBLISHED
ISO 21395-1:2020

NOW

IN_DEVELOPMENT
ISO/WD 21395-1
20.60 Close of comment period
Apr 17, 2026