prEN ISO 8980-4

SLOVENSKI STANDARD
01-junij-2025
Očesna optika – Nebrušena zglajena stekla očal - 4. del: Specifikacije in preskusne
metode za protiodbojno in hidrofobno prevleko (ISO/DIS 8980-4:2025)
Ophthalmic optics - Uncut finished spectacle lenses - Part 4: Specifications and test
methods for anti-reflective and hydrophobic coatings (ISO/DIS 8980-4:2025)
Augenoptik - Rohkantige fertige Brillengläser - Teil 4: Anforderungen und Prüfverfahren
für die Eigenschaften von reflexmindernde und hydrophobe Vergütungen (ISO/DIS 8980-
4:2025)
Optique ophtalmique - Verres de lunettes finis non détourés - Partie 4: Spécifications et
méthodes d'essai relatives aux propriétés des traitements antireflet et hydrophobe
(ISO/DIS 8980-4:2025)
Ta slovenski standard je istoveten z: prEN ISO 8980-4
ICS:
11.040.70 Oftalmološka oprema Ophthalmic equipment
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
International
Standard
ISO/DIS 8980-4
ISO/TC 172/SC 7
Ophthalmic optics — Uncut finished
Secretariat: DIN
spectacle lenses —
Voting begins on:
Part 4: 2025-04-18
Specifications and test methods
Voting terminates on:
2025-07-11
for the properties of anti-reflective
coatings and hydrophobic coatings
ICS: 11.040.70
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document is circulated as received from the committee secretariat.
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NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION.
Reference number
ISO/DIS 8980-4:2025(en)
DRAFT
ISO/DIS 8980-4:2025(en)
International
Standard
ISO/DIS 8980-4
ISO/TC 172/SC 7
Ophthalmic optics — Uncut finished
Secretariat: DIN
spectacle lenses —
Voting begins on:
Part 4:
Specifications and test methods
Voting terminates on:
for the properties of anti-reflective
coatings and hydrophobic coatings
ICS: 11.040.70
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document is circulated as received from the committee secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
© ISO 2025
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
STANDARDS MAY ON OCCASION HAVE TO
ISO/CEN PARALLEL PROCESSING
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
BE CONSIDERED IN THE LIGHT OF THEIR
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NOTIFICATION OF ANY RELEVANT PATENT
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Website: www.iso.org
Published in Switzerland Reference number
ISO/DIS 8980-4:2025(en)
ii
ISO/DIS 8980-4:2025(en)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Requirements . 3
4.1 General requirements .3
4.2 Usable diameter of coated area .3
4.3 Luminous and mean reflectances . .3
4.4 Water repellency .3
4.5 Durability .3
5 Testing. 3
5.1 General .3
5.2 Anti-reflective coating .4
5.2.1 Method of determination of reflectance .4
5.2.2 Determination of spectral reflectance values.4
5.2.3 Determination of luminous reflectance .4
5.2.4 Determination of mean reflectance .4
5.2.5 Information to be made available on request .5
5.3 Hydrophobic coating .5
5.3.1 Contact angle measurement apparatus .5
5.3.2 Water for testing . .5
5.3.3 Sample.5
5.3.4 Procedure .6
5.4 Determination of durability . .6
6 Reference to this part of ISO 8980 . 7
Annex A (informative) Significance of ρ and ρ in the description of anti-reflective coated
v M
lenses . 8
Annex B (normative) Environmental sequence . 9
Annex C (normative) Rubbing sequence procedure .11
Annex D (normative) Evaluation conditions .13
Annex E (informative) Examples of lenses passing and failing the visual evaluation .15
Annex F (informative) Examples of environmental sequence .16
Annex G (informative) Examples of a rubbing tool and components .18
Annex H (informative) Example of a contact angle test apparatus .20
Bibliography .22

iii
ISO/DIS 8980-4:2025(en)
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 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO [had/had not] received notice of
(a) patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 172, Optics and photonics, Subcommittee SC 7,
Ophthalmic optics and instruments.
This third edition cancels and replaces the second edition (ISO 8980-4:2006), which has been technically
revised.
The main changes are as follows:
— the title;
— the scope has been expanded to include hydrophobic coating properties;
— the scope has been defined to exclude requirements and test methods found in other standards within
the 8980 series;
— normative references, terms and definitions relating to hydrophobic properties have been added in
Clause 2 and 3;
— testing methods for hydrophobic coating properties have been added in Clause 5 and informative and
normative Annexes C, D and E.
A list of all parts in the ISO 8980 series can be found on the ISO website.
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

iv
ISO/DIS 8980-4:2025(en)
— Part 5: Minimum requirements for spectacle lens surfaces claimed to be abrasion-resistant
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

v
DRAFT International Standard ISO/DIS 8980-4:2025(en)
Ophthalmic optics — Uncut finished spectacle lenses —
Part 4:
Specifications and test methods for the properties of anti-
reflective coatings and hydrophobic coatings
1 Scope
This part of ISO 8980 specifies optional requirements and test methods for anti-reflective and hydrophobic
coating properties on spectacle lenses.
This part of ISO 8980 does not deal with the following topics:
— requirements and test methods incorporated into other ISO 8980 series standards;
— the colour of the reflected light.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements 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.
ISO 48, Rubber, vulcanized or thermoplastic — Determination of hardness (hardness between 10 IRHD and
100 IRHD)
ISO 3696, Water for analytical laboratory use — Specification and test methods
ISO 8980-1, Ophthalmic optics — Uncut finished spectacle lenses — Part 1: Specifications for single-vision and
multifocal lenses
ISO 8980-2, Ophthalmic optics — Uncut finished spectacle lenses — Part 2: Specifications for power-variation lenses
ISO 8980-3, Ophthalmic optics — Uncut finished spectacle lenses — Part 3: Transmittance specifications and
test methods
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 following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/

ISO/DIS 8980-4:2025(en)
3.1
Durability

ability to resist deterioration of its reflectance characteristics, over time, in normal use
Note 1 to entry: The major factors contributing to deterioration of an anti-reflective coating are rubbing, heat, UV
radiation and humidity.
Note 2 to entry: The main failure mechanism affecting the durability of anti-reflective coatings is a loss of adhesion.
Therefore, requirements of this part of ISO 8980 are related to anti-reflective coating adhesion.
3.2
static contact angle
θ
static contact angle θ angle between a plane solid surface and the tangent drawn in the vertical plane at
the interface between the plane solid surface and the surface of a droplet of liquid resting on the surface,
normally in air
Note 1 to entry: The static contact angle is illustrated in Figure 1.
Key
1 surface of the droplet of liquid
2 surface of the lens
Figure 1 — Illustration of contact angle
3.3
sessile drop method
method of obtaining a contact angle by placing a droplet on a solid surface
3.4
water repellent coating
coating on the top of the lens surface or surface coating having hydrophobic and anti-fouling functions
Note 1 to entry: A number of trade names, such as self-cleaning, hydrophobic, water repellent, waterproof, etc., are
applied to this type of coating.
Note 2 to entry: It is generally considered that a hydrophobic surface has a water contact angle that is greater than or
equal to 90°.
ISO/DIS 8980-4:2025(en)
4 Requirements
4.1 General requirements
Anti-reflective coated and hydrophobic coated lenses shall comply with the general requirements concerning
the finished spectacle lens specifications in ISO 8980-1, ISO 8980-2, ISO 8980-3 and ISO 14889. This
document applies to lenses that are antireflective coated or hydrophobic coated, or a combination of both.
NOTE 1 For further information on the properties of anti-reflective coatings, see informative Annex A.
NOTE 2 The reflectance characteristics of an anti-reflective coating should not significantly change due to
deterioration of the coating in normal use.
4.2 Usable diameter of coated area
The usable diameter of the coated area for uncut finished spectacle lenses shall be ⩾(dn-4) mm, where dn is
the nominal diameter of the lens, in millimetres, indicated by the manufacturer.
4.3 Luminous and mean reflectances
The luminous reflectance ρ and the mean reflectance ρ of an anti-reflective coated lens shall be determined
V M
by the method specified in 5.2.2.
If the manufacturer specifies values for luminous and mean reflectances, the measured values shall not
exceed the specified values by more than 20 %.
When determined as described in 5.4, the luminous reflectance ρ of any anti-reflective coated lens surface
V
shall be less than 2,5 %.
4.4 Water repellency
The static contact angle of water for the front surface of a lens with hydrophobic coating shall be determined
by the method specified in 5.3.
For lenses which the hydrophobic property is claimed, the mean contact angle of water should be greater
than or equal to 90°.
4.5 Durability
Under the conditions described in the test method given in 5.4, five consecutively tested lenses shall be free
of significant loss of adhesion as defined in 5.4.4.
A product meets the durability requirements of this part of ISO 8980 if all five lenses tested satisfy this
criterion.
5 Testing
5.1 General
This clause specifies type test methods for anti-reflective and hydrophobic coatings on spectacle lenses. At
least 24 h shall elapse after coating before any type test is carried out. Lenses shall be stored at a temperature
of 20 °C to 26 °C.
ISO/DIS 8980-4:2025(en)
5.2 Anti-reflective coating
5.2.1 Method of determination of reflectance
5.2.1.1 Apparatus
Use any dual-beam or single-beam spectrophotometer with an incident angle not larger than 17° and
with a measurement accuracy sufficient to give the value of the spectral reflectance at all wavelengths λ
between 380 nm and 780 nm with an uncertainty of less than 0,1 % (for example, an anti-reflective coating
quoted as having 0,5 % reflectance may be measured as having 0,4 % to 0,6 % reflectance). The wavelength
increment of measurement shall not be more than 5 nm. The spectral bandwidth (full width at half maximum,
FWHM) shall not exceed 5 nm.
The calibration specimen shall have a surface curvature within 0,50 D of that of the spectacle lens to be
tested. The back surface of this specimen shall be designed such that no reflection will interfere with
the measurement (e.g. both frosted and painted matt black). The calibration specimen shall be of known
refractive index n(λ) (uncertainty Δn < 0,001) and have no coating (which could affect its surface reflective
properties). The surface shall be cleaned.
5.2.1.2 Spectacle lens preparation
The surface of the spectacle lens under test shall have a radius of curvature greater than 80 mm. The back
surface of the lens shall be designed such that no reflection will interfere with the measurement (e.g. both
frosted and painted matt black). The surface shall be cleaned.
5.2.1.3 Measurement
Insert the calibration specimen and calibrate the spectrophotometer to give a value of 100 %. Then insert
the spectacle lens. The spectrophotometer will give the value of the spectacle lens to calibration specimen
spectral reflectance ratio R (λ) in %, expressed as percentage. By using this technique, any error due to
T
surface curvature will be eliminated.
Measure the spectacle lens to calibration specimen spectral reflectance ratio over the range 380 nm
to 780 nm, at least every 5 nm.
5.2.2 Determination of spectral reflectance values
The value of the calibration specimen surface spectral reflectance R (λ) is calculated theoretically from the
C
refractive index.
n λ −1
 () 
R ()λ = (1)
C  
n()λ +1
 
The value of the spectacle lens surface spectral reflectance is calculated by multiplying the calibration
specimen spectral reflectance value by the spectacle lens-to-calibration specimen spectral reflectance ratio:
ρ(λ) = R (λ) × R (λ) (2)
C T
5.2.3 Determination of luminous reflectance
Calculate the luminous reflectance ρ using both the spectral reflectance values ρ(λ) and the equation given
V
in ISO 13666.
5.2.4 Determination of mean reflectance
Calculate the mean reflectance ρ using both the spectral reflectance values ρ(λ) and the equation given
M
in ISO 13666.
ISO/DIS 8980-4:2025(en)
5.2.5 Information to be made available on request
The values of the luminous reflectance ρ and mean reflectance ρ and the spectral reflectance curve shall
V M
be made available on request for a typical surface with a radius of curvature not less than 80 mm.
5.3 Hydrophobic coating
5.3.1 Contact angle measurement apparatus
Equipment that can measure the static contact angle shall be used. Image acquisition and processing can be used
to determine the static contact angle. This can be achieved with macrophotography of the droplet, or porjection
of the droplet onto a screen. An example of a projection apparatus is given in Annex H. If using a projection
aparatus, direct measurement of the image on the screen or after photography can be used. Alternative
apparatus based on image acquisition and processing may be used to calculate the static contact angle.
5.3.2 Water for
...