SIST EN ISO 8980-3:2014

Ophthalmic optics - Uncut finished spectacle lenses - Part 3: Transmittance specifications and test methods (ISO 8980-3:2013)

This part of ISO 8980 specifies requirements for the transmittance properties of uncut finished spectacle lenses and mounted pairs, including attenuation of solar radiation. This part of ISO 8980 is not applicable to - spectacle lenses having particular transmittance or absorption characteristics prescribed for medical reasons; - products where specific personal protective equipment transmittance standards apply; - products intended for direct observation of the sun, such as for solar-eclipse viewing.

Augenoptik - Rohkantige fertige Brillengläser - Teil 3: Transmissionsanforderungen und Prüfverfahren (ISO 8980-3:2013)

Dieser Teil von ISO 8980 legt die Anforderungen für die Transmissionseigenschaften rohkantiger fertiger Brillengläser sowie fertig montierter Brillengläser fest, einschließlich solcher Gläser, die die Sonnenstrahlung
- zum allgemeinen Gebrauch - dämpfen. Dieser Teil von ISO 8980 gilt nicht für:
- Brillengläser mit besonderen Transmissionseigenschaften oder Absorptionseigenschaften, die aus medizinischen Gründen verordnet werden;
- Produkte für die besondere Normen hinsichtlich der Transmissionseigenschaften für persönliche Schutzausrüstungen
gelten;
- Produkte zur direkten Beobachtung der Sonne, wie beispielsweise bei einer Sonnenfinsternis.
ANMERKUNG Optische und geometrische Anforderungen an rohkantige fertige Brillengläser sind in ISO 8980-1 und
ISO 8980-2 festgelegt; für fertig montierte Brillengläser sind sie in ISO 21987 festgelegt.

Optique ophtalmique - Verres de lunettes finis non détourés - Partie 3: Spécifications relatives au facteur de transmission et méthodes d'essai (ISO 8980-3:2013)

L'ISO 8980-3:2013 spécifie les exigences relatives aux propriétés de transmission des verres de lunettes et verres montés finis non détourés, ainsi qu'à l'atténuation du rayonnement solaire.

Očesna optika - Nebrušena zglajena stekla očal - 3. del: Specifikacije za prepustnost in preskusne metode (ISO 8980-3:2013)

General Information

• Status: Withdrawn
• Public Enquiry End Date: 09-Jan-2012
• Publication Date: 02-Jan-2014
• Withdrawal Date: 21-Aug-2022
• ICS: 11.040.70 - Ophthalmic equipment
• Technical Committee: VAZ - Healthcare
• Current Stage: 9900 - Withdrawal (Adopted Project)
• Start Date: 04-Aug-2022
• Due Date: 27-Aug-2022
• Completion Date: 22-Aug-2022
• Ref Project: EN ISO 8980-3:2013 - Ophthalmic optics - Uncut finished spectacle lenses - Part 3: Transmittance specifications and test methods (ISO 8980-3:2013)

Relations

• Replaced By: SIST EN ISO 8980-3:2022 - Ophthalmic optics - Uncut finished spectacle lenses - Part 3: Transmittance specifications and test methods (ISO 8980-3:2022)
• Effective Date: 01-Sep-2022
• Replaces: SIST EN ISO 8980-3:2005 - Ophthalmic optics - Uncut finished spectacle lenses - Part 3: Transmittance specifications and test methods (ISO 8980-3:2003)
• Effective Date: 01-Feb-2014
• Replaces: SIST EN ISO 8980-3:2005 - Ophthalmic optics - Uncut finished spectacle lenses - Part 3: Transmittance specifications and test methods (ISO 8980-3:2003)
• Effective Date: 08-Jun-2022

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN ISO 8980-3:2014
01-februar-2014
1DGRPHãþD
SIST EN ISO 8980-3:2005
2þHVQDRSWLND1HEUXãHQD]JODMHQDVWHNODRþDOGHO6SHFLILNDFLMH]D
SUHSXVWQRVWLQSUHVNXVQHPHWRGH,62
Ophthalmic optics - Uncut finished spectacle lenses - Part 3: Transmittance
specifications and test methods (ISO 8980-3:2013)
Augenoptik - Rohkantige fertige Brillengläser - Teil 3: Transmissionsanforderungen und
Prüfverfahren (ISO 8980-3:2013)
Optique ophtalmique - Verres de lunettes finis non détourés - Partie 3: Spécifications
relatives au facteur de transmission et méthodes d'essai (ISO 8980-3:2013)
Ta slovenski standard je istoveten z: EN ISO 8980-3:2013
ICS:
11.040.70 Oftalmološka oprema Ophthalmic equipment
SIST EN ISO 8980-3:2014 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO 8980-3:2014

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SIST EN ISO 8980-3:2014


EUROPEAN STANDARD
EN ISO 8980-3

NORME EUROPÉENNE

EUROPÄISCHE NORM
October 2013
ICS 11.040.70 Supersedes EN ISO 8980-3:2004
English Version
Ophthalmic optics - Uncut finished spectacle lenses - Part 3:
Transmittance specifications and test methods (ISO 8980-
3:2013)
Optique ophtalmique - Verres de lunettes finis non détourés Augenoptik - Rohkantige fertige Brillengläser - Teil 3:
- Partie 3: Spécifications relatives au facteur de Transmissionsanforderungen und Prüfverfahren (ISO 8980-
transmission et méthodes d'essai (ISO 8980-3:2013) 3:2013)
This European Standard was approved by CEN on 7 September 2013.

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 lists and bibliographical references concerning such national
standards may be obtained on application to the CEN-CENELEC Management Centre 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 responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same
status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United
Kingdom.





EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2013 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 8980-3:2013: E
worldwide for CEN national Members.

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SIST EN ISO 8980-3:2014
EN ISO 8980-3:2013 (E)
Contents Page
Foreword .3

2

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SIST EN ISO 8980-3:2014
EN ISO 8980-3:2013 (E)
Foreword
This document (EN ISO 8980-3:2013) has been prepared by Technical Committee ISO/TC 172 "Optics and
photonics" 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 national standard, either by publication of an identical
text or by endorsement, at the latest by April 2014, and conflicting national standards shall be withdrawn at the
latest by October 2016.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 8980-3:2004.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech
Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece,
Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom.
Endorsement notice
The text of ISO 8980-3:2013 has been approved by CEN as EN ISO 8980-3:2013 without any modification.

3

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SIST EN ISO 8980-3:2014

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SIST EN ISO 8980-3:2014
INTERNATIONAL ISO
STANDARD 8980-3
Third edition
2013-10-01
Ophthalmic optics — Uncut finished
spectacle lenses —
Part 3:
Transmittance specifications and test
methods
Optique ophtalmique — Verres de lunettes finis non détourés —
Partie 3: Spécifications relatives au facteur de transmission et
méthodes d’essai
Reference number
ISO 8980-3:2013(E)
©
ISO 2013

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SIST EN ISO 8980-3:2014
ISO 8980-3:2013(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2013
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior
written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of
the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail [e-mail]
Web www.iso.org
Published in Switzerland
ii © ISO 2013 – All rights reserved

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SIST EN ISO 8980-3:2014
ISO 8980-3:2013(E)

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols . 4
5 Classification . 4
6 Requirements . 4
6.1 General . 4
6.2 General transmittance requirements . 5
6.3 Spectral transmittance requirements of spectacle lenses intended for road use
and driving . 6
6.4 Additional transmittance requirements for special types of spectacle lenses . 6
6.5 Resistance to radiation . 7
7 Test methods . 8
7.1 General . 8
7.2 Spectral transmittance . 8
7.3 Luminous transmittance and relative visual attenuation coefficient (quotient) . . 8
7.4 Ultraviolet transmittance . 8
7.5 Transmittance properties of photochromic spectacle lenses and
photochromic specimens . 9
7.6 Test methods for polarizing spectacle lenses .11
7.7 Determination of resistance to radiation .13
8 Identification .14
Annex A (normative) Spectral data for calculating relative visual attenuation quotients for
incandescent signal lights .15
Annex B (normative) Calculation of solar UV transmittance values .20
Annex C (normative) Cut-on filter for UV filtering .22
Annex D (informative) Spectral data for calculating relative visual attenuation quotients for LED
signal lights .25
Annex E (informative) Spectral radiation risks .28
Annex F (informative) Example of the calculation of luminous transmittance,τ .29
V
Bibliography .31
© ISO 2013 – All rights reserved iii

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SIST EN ISO 8980-3:2014
ISO 8980-3:2013(E)

Foreword
ISO (the International Organization for Standardization) 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 to be represented on that committee. International
organizations, 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.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2. www.iso.org/directives
Attention 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. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received. www.iso.org/patents
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
The committee responsible for this document is ISO/TC 172, Optics and photonics, Subcommittee SC 7,
Ophthalmic optics and instruments.
This third edition cancels and replaces the second edition (ISO 8980-3:2003), which has been technically
revised. In particular, the requirement in 6.3.2 for lenses intended for road use and driving has been
amended with an extension of three years for the continued manufacture of existing products.
ISO 8980 consists of the following parts, under the general title Ophthalmic optics — Uncut finished
spectacle lenses:
— Part 1: Specifications for single-vision and multifocal lenses
— Part 2: Specifications for progressive power lenses
— Part 3: Transmittance specifications and test methods
— Part 4: Specifications and test methods for anti-reflective coatings
— Part 5: Minimum requirements for spectacle lens surfaces claimed to be abrasion-resistant
iv © ISO 2013 – All rights reserved

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SIST EN ISO 8980-3:2014
INTERNATIONAL STANDARD ISO 8980-3:2013(E)
Ophthalmic optics — Uncut finished spectacle lenses —
Part 3:
Transmittance specifications and test methods
1 Scope
This part of ISO 8980 specifies requirements for the transmittance properties of uncut finished spectacle
lenses and mounted pairs, including attenuation of solar radiation.
This part of ISO 8980 is not applicable to
— spectacle lenses having particular transmittance or absorption characteristics prescribed for
medical reasons;
— products where specific personal protective equipment transmittance standards apply;
— products intended for direct observation of the sun, such as for solar-eclipse viewing.
NOTE Optical and geometric requirements for uncut finished spectacle lenses are specified in ISO 8980-1
and ISO 8980-2, and for mounted lenses, in ISO 21987.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 11664-1, Colorimetry — Part 1: CIE standard colorimetric observers
ISO 11664-2, Colorimetry — Part 2: CIE standard illuminants
ISO 13666, Ophthalmic optics — Spectacle lenses — Vocabulary
ISO 14889, Ophthalmic optics — Spectacle lenses — Fundamental requirements for uncut finished lenses
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 13666 apply.
NOTE 1 For the convenience of the reader, the following definitions have been reproduced from ISO 13666.
NOTE 2 Absorptance, reflectance and transmittance are usually expressed as percentages. The equations in
this clause are written in this form. Although the definitions use integrals, in practice summation, typically at
1 nm, 5 nm or 10 nm intervals, is performed to calculate the various transmittances.
3.1
mean UV-A transmittance
τ
UVA
mean transmittance between 315 nm and 380 nm
380 nm
1
ττ=×100 ()λλ⋅d %
UVA
∫
65 nm
315 nm
© ISO 2013 – All rights reserved 1

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SIST EN ISO 8980-3:2014
ISO 8980-3:2013(E)

[ISO 13666:2012, definition 15.3.1]
3.2
solar UV-A transmittance
τ
SUVA
mean of the spectral transmittance between 315 nm and 380 nm weighted by the solar radiation
distribution E (λ) at sea level, for air mass 2, and the relative spectral effectiveness function for
s
UV radiation S(λ)
380 nm
τλ()⋅⋅ES()λλ()⋅dλ
s
∫
315 nm
τ =×100 %
SUVA
3880 nm
ES()λλ⋅⋅() dλ
s
∫
315 nm
Note 1 to entry: The complete weighting function W(λ) is the product of E (λ) and S(λ) and is given in Table B.1.
s
[SOURCE: ISO 13666:2012, definition 15.3.2]
3.3
solar UV-B transmittance
τ
SUVB
mean of the spectral transmittance between 280 nm and 315 nm weighted by the solar radiation
distribution E (λ) at sea level, for air mass 2, and the relative spectral effectiveness function for UV
S
radiation S(λ)
315 nm
τλ()⋅⋅ES()λλ()⋅dλ
s
∫
280 nm
τ =×100 %
SUVB
315 nm
ES()λλ⋅⋅() dλ
s
∫
280 nnm
Note 1 to entry: The complete weighting function W(λ) is the product of E (λ) and S(λ) and is given in Table B.1.
s
[SOURCE: ISO 13666:2012, definition 15.3.3]
3.4
luminous transmittance
τ
V
ratio of the luminous flux transmitted by the lens or filter to the incident luminous flux
780 nm
τλ()⋅VS()λλ⋅ ()⋅dλ
D65
∫
380 nm
τ =×100 %
V
780 nm
VSλλ⋅ ⋅ dλ
() ()
D65
∫
380 nm
where
τ(λ) is the spectral transmittance of the spectacle lens;
V(λ) is the spectral luminous efficiency function for daylight (see ISO 11664-1);
S (λ) is the spectral distribution of radiation of CIE standard illuminant D65 (see ISO 11664-2).
D65
Note 1 to entry: The spectral values of the product of the spectral radiation distributions S (λ) of the CIE
D65
standard illuminant D65 and the eye’s spectral luminous efficiency function V(λ) are given in Table A.2.
2 © ISO 2013 – All rights reserved

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SIST EN ISO 8980-3:2014
ISO 8980-3:2013(E)

[SOURCE: ISO 13666:2012, definition 15.4]
3.5
relative visual attenuation coefficient (quotient) for incandescent traffic signal light
recognition/detection
Q-value
ratio of the luminous transmittance of a tinted lens for the spectral radiant power distribution of the
light emitted by a traffic signal τ to the luminous transmittance of the same lens for CIE standard
signal
illuminant D65 (τ )
V
τsignal
Q =
τ
V
where
τ is the luminous transmittance of the lens for the spectral radiant power distribution of the
signal
traffic signal light.
Note 1 to entry: Q-values can be determined for each of blue, green, amber (yellow) and red signal lights. τ is
signal
given by the equation:
780 nm
τλ()⋅⋅τλ() VS()λλ⋅⋅() dλ
A
S
∫
380 nm
τ signal=×100 %
780 nm
τλ()⋅V (λ))(⋅⋅S λλ) d
S A
∫
380 nm
where
τ (λ) is the spectral transmittance of the traffic signal lens;
S
S (λ) is the spectral distribution of radiation of CIE standard illuminant A (or 3 200 K light
A
source for blue signal light) (see ISO 11664-2);
Note 2 to entry: The spectral values of the products of the spectral distributions S (λ) of the illuminant A, the
A
spectral luminous efficiency function V(λ) of the eye and the spectral transmittance τ (λ) of the traffic signal lens
S
are given in Table A.1, where E (λ)=S (λ)×τ (λ).
Signal A S
Note 3 to entry: Calculations are currently based on the measured values of E(λ) for traffic signal lights using
incandescent quartz-halogen lamps. They previously used the product τ (λ) ·S (λ) of the spectral transmittance
S A
of the traffic signal filter and the spectral distribution of radiation of CIE standard illuminant A. Calculations
using the values for quartz-halogen lamps and LED signals will give different results
Note 4 to entry: Adapted from ISO 13666:2012, definition 15.5.
3.6
polarizing efficiency
property of a polarizing lens, describing the percentage of the transmitted light that is polarised, defined
by the equation
ττ−
p,maxp,min
P=×100 %
ττ+
p,maxp,min
where
© ISO 2013 – All rights reserved 3

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SIST EN ISO 8980-3:2014
ISO 8980-3:2013(E)

τ is the maximum value of luminous transmittance as determined with 100% linearly polar-
p,max
ised radiation;
τ is the minimum value of luminous transmittance as determined with 100% linearly polar-
p,min
ised radiation.
Note 1 to entry: Adapted from ISO 13666:2012, definition 8.1.12.3.
4 Symbols
The symbols for the characteristic luminous transmittances of photochromic lenses are given in Table 1.
Table 1 — Symbols for the characteristic luminous transmittances of photochromic lenses
Symbols Characteristic luminous transmittances
τ Luminous transmittance in the faded state as reached at (23 ± 2) °C after specified condi-
V0
tioning.
τ Luminous transmittance in the darkened state as reached at (23 ± 2) °C after specified
V1
irradiation simulating mean outdoor conditions.
τ Luminous transmittance in the darkened state as reached at (5± 2) °C after specified irra-
VW
diation simulating outdoor conditions at low temperatures.
τ Luminous transmittance in the darkened state as reached at (35± 2) °C after specified
VS
irradiation simulating outdoor conditions at high temperatures.
τ Luminous transmittance in the darkened state as reached at (23 ± 2) °C after specified
VA
irradiation simulating reduced light conditions.
5 Classification
Spectacle lenses are classified with respect to transmittance as follows:
a) clear spectacle lenses, having no intended colour (including grey) in transmission;
b) uniformly tinted spectacle lenses;
c) gradient-tinted spectacle lenses;
d) photochromic spectacle lenses;
e) polarizing spectacle lenses.
NOTE Two or more of the above classifications may be combined.
6 Requirements
6.1 General
The fundamental requirements for uncut finished lenses, including reference to 6.3 in this part of
ISO 8980, are in ISO 14889. The requirements shall apply at a temperature of (23 ± 5) °C, and shall apply
at the design reference point, unless specified otherwise.
4 © ISO 2013 – All rights reserved

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SIST EN ISO 8980-3:2014
ISO 8980-3:2013(E)

6.2 General transmittance requirements
6.2.1 Tint descriptions, categories, and UV transmittance requirements
Spectacle lenses shall be attributed to one of five tint descriptions or luminous transmittance categories
as specified in Table 2, and shall be tested as described in Clause 7.
A spectacle lens intended to have a luminous transmittance τ that is in categories 0, 1, 2 and 3 shall have
V
a luminous transmittance at its design reference point that shall not lie outside the limits of the stated
category by more than 2 % absolute. For example, a lens intended to have a luminous transmittance
of 40 % but actually having a transmittance of 45 % shall comply with the UV requirements of a
category 2 lens.
A spectacle lens intended to have a luminous transmittance τ that is in category 4 shall have a luminous
V
transmittance τ at its design reference point that shall not lie outside the limits of that category by
V
more than 20 % relative to the stated luminous transmittance.
All lenses shall meet the specified UV requirements corresponding to their intended luminous
transmittance τ in Table 2, but those clear glass spectacle lenses of category 0 for which no specific
V
claim is made as to UV transmittance performance are excluded from the UV requirements of Table 2.
NOTE This exclusion applies because some clear crown glass lenses cannot meet the UV-B requirement.
6.2.2 Tolerances on luminous transmittance of tinted lenses
It is recommended that a tint should be ordered by reference to a manufacturer’s sample. Such a tint
shall not be obviously dissimilar from the tint of the sample and its assessment is not restricted by its
luminous transmittance τ measured by spectrophotometer.
V
For a lens ordered by a specific luminous transmittance τ shall have a measured τ at the design
V V
reference point within ± 8 % absolute of that ordered. The tint of the two lenses of a pair should not be
obviously dissimilar.
Table 2 — Categories for luminous transmittance and the related permissible transmittance in
the ultraviolet solar spectral range
Visible spectral range Ultraviolet spectral range
Range of luminous Maximum value of solar Maximum value of solar
transmittance UV-A transmittance UV-B transmittance
τ τ τ
V SUVA SUVB
Luminous
to > 315 nm to 380 nm > 280 nm to 315 nm
Tint transmit- from over
description tance %
% UV-A UV-B
category
Clear or
very light 0 80,0 100 τ 0,05 τ
V V
tint
Light tint 1 43,0 80,0 τ 0,05 τ
V V
1,0 % absolute or 0,05 τ ,
V
Medium tint 2 18,0 43,0 0,5 τ
V
whichever is greater
Dark tint 3 8,0 18,0 0,5 τ 1,0 % absolute
V
Very dark 1,0 % absolute or 0,25 τ ,
V
4 3,0 8,0 1,0 % absolute
tint whichever is greater
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SIST EN ISO 8980-3:2014
ISO 8980-3:2013(E)

6.3 Spectral transmittance requirements of spectacle lenses intended for road use and
driving
6.3.1 General
Spectacle lenses having a luminous transmittance τ less than or equal to 8 % are not intended for road
V
use and driving. This clause therefore does not contain requirements for such lenses.
6.3.2 Spectral transmittance
The spectral transmittance τ(λ) at any wavelength in the range 475 nm to 650 nm shall be not less than
0,2 τ .
V
For a period of three years from the date of publication of this part of ISO 8980, products that are
existing at the date of publication of this part of ISO 8980 that satisfy the requirement that the spectral
transmittance, τ(λ) at any wavelength in the range 500 nm to 650 nm shall be not less than 0,2 τ will
V
be deemed to pass the requirement of this part of ISO 8980.
6.3.3 Daylight use
When using illuminant D65, the luminous transmittance τ of spectacle lenses for road use and driving
V
during daylight shall be more than 8 % at the design reference point.
6.3.4 Driving in twilight or at night
Spectacle lenses with a luminous transmittance τ less than 75 % shall not be used for road use and
V
driving in twilight or at night. In the case of photochromic spectacle lenses, this requirement applies
when tested in accordance with 7.5.3.5.
6.3.5 Relative visual attenuation coefficient (quotient) for recognition/detection of incandes-
cent signal lights
Spectacle lenses shall have a relative visual attenuation coefficient (quotient) Q not less than:
a) 0,8 for Q ;
red
b) 0,6 for Q ;
yellow
c) 0,6 for Q ;
green
d) 0,4 for Q .
blue
The relative visual attenuation coefficient (quotient) Q shall be calculated according to 3.5, in accordance
with Table A.1.
6.4 Additional transmittance requirements for special types of spectacle lenses
6.4.1 Photochromic spectacle lenses
6.4.1.1 General
Photochromic spectacle lenses are usually attributed to two categories, corresponding to the faded state
and to the darkened state. The faded and darkened state transmittances shall be determined according
to the method in 7.5. The UV transmittance in both the faded and darkened states shall conform to the
values specified for both categories in Table 2.
NOTE It is not required to claim the category of the lens in its darkened state.
6 © ISO 2013 – All rights reserved

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SIST EN ISO 8980-3:2014
ISO 8980-3:2013(E)

6.4.1.2 Photochromic response
When tested by the methods described in 7.5.3.1 to 7.5.3.3, the ratio of the luminous transmittance of
a photochromic specimen (see 7.5.1) in its faded state τ and, after 15 min irradiation, in its darkened
V0
state τ shall be at least 1,25, i.e.
V1
τ
V0
≥12, 5
τ
V1
6.4.1.3 Photochromic response at various temperatures
If photochromic temperature influence is stated, it shall be determined by measuring the luminous
transmittance of the specimen (see 7.5.1) in the darkened state using the procedure described in 7.5.3.6
at 5 °C (τ ), 23 °C (τ ) and 35 °C (τ ).
VW V1 VS
NOTE The manufacturer may use additional temperatures, provided this information is made available.
6.4.1.4 Photochromic response at moderate light levels
If the photochromic response at moderate light levels is stated, it shall be determined by measuring the
luminous transmittance of the specimen (see 7.5.1) in the darkened state τ using the procedure described
VA
in 7.5.3.4 after exposure to the illumination specified in 7.5.2.1 attenuated to an intensity of 30 %.
6.4.2 Polarizing spectacle lenses
6.4.2.1 Individual uncut polarizing lenses
When tested according to the method in 7.6, the polarizing efficiency as calculated in 3.6 shall be > 78 %
for luminous transmittance categories 2, 3, 4 and > 60 % for luminous transmittance category 1.
If there is a marking on the spectacle lens indicating the intended direction of horizontal orientation,
then the actual plane of transmittance shall be at (90 ± 3)° from this marking.
6.4.2.2 Mounted pairs of polarizing lenses
If the lenses mounted in spectacles are claimed to be polarizing for
...