FprEN ISO 18490

SLOVENSKI STANDARD
01-julij-2025
Neporušitvene preiskave - Vrednotenje ostrine vida za osebje, ki izvaja
neporušitvene preiskave (NDT) (ISO/DIS 18490:2025)
Non-destructive testing - Evaluation of vision acuity of NDT personnel (ISO/DIS
18490:2025)
Zerstörungsfreie Prüfung - Bestimmung der Sehfähigkeit von ZfP-Personal (ISO/DIS
18490:2025)
Essais non destructifs - Évaluation de l'acuité visuelle du personnel END (ISO/DIS
18490:2025)
Ta slovenski standard je istoveten z: prEN ISO 18490
ICS:
03.100.30 Vodenje ljudi Management of human
resources
19.100 Neporušitveno preskušanje Non-destructive testing
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
International
Standard
ISO/DIS 18490
ISO/TC 135/SC 7
Non-destructive testing —
Secretariat: SCC
Evaluation of vision acuity of NDT
Voting begins on:
personnel
2025-05-01
Essais non destructifs — Évaluation de l'acuité visuelle du
Voting terminates on:
personnel END
2025-07-24
ICS: 03.100.30; 19.100
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 18490:2025(en)
DRAFT
ISO/DIS 18490:2025(en)
International
Standard
ISO/DIS 18490
ISO/TC 135/SC 7
Non-destructive testing —
Secretariat: SCC
Evaluation of vision acuity of NDT
Voting begins on:
personnel
Essais non destructifs — Évaluation de l'acuité visuelle du
Voting terminates on:
personnel END
ICS: 03.100.30; 19.100
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
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BE CONSIDERED IN THE LIGHT OF THEIR
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NATIONAL REGULATIONS.
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TO SUBMIT, WITH THEIR COMMENTS,
CH-1214 Vernier, Geneva
NOTIFICATION OF ANY RELEVANT PATENT
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Website: www.iso.org
Published in Switzerland Reference number
ISO/DIS 18490:2025(en)
ii
ISO/DIS 18490:2025(en)
Contents Page
Foreword .iv
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Chart print quality and marking . 2
5 Health and safety requirements . 2
6 Personnel administering the test . 2
7 Near and Far Vision Test charts . 2
8 Test procedure . 2
8.1 General .2
8.2 Illumination level (normative) .3
8.3 Luminance (informative) .3
8.4 Eye to chart distance .3
8.5 Vision Correction .3
8.6 The tests .3
9 Acceptance levels. 4
Annex A (informative) Radner Chart (Not to scale) . 5
Annex B (informative) Snellen Chart (Not to scale) . 6
Annex C (informative) Landolt Chart (Not to scale) . 7
Annex D (informative) Ishihara Chart (Not to Scale) . 8
Annex E (informative) Sample Colour Trade Test Exam . 9
Annex F (informative) Corresponding Reading Acuity Notations for Test Distances of 40 cm
(16 inches) and 32 cm (12.5 inches) .12
Annex G (informative) Grey Scale Perception Testing .13
Annex H (informative) Low Contrast Visual Acuity. 14
Bibliography .15

iii
ISO/DIS 18490:2025(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 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 135, Non-destructive testing, SC 7, Personnel
Qualification in collaboration with European Committee for Standardization (CEN), in accordance with the
Agreement on technical cooperation between ISO and CEN (Vienna Agreement).
This second edition cancels and replaces the first edition (ISO 18490:2015), which has been technically
revised.
The main changes are as follows:
— Far and Colour vision acuity of NDT personnel added to the Scope
— Reference to EN 4179 Aerospace series - Qualification and approval of personnel for non-destructive
testing removed
— Reference to ISO 8596:2017 Ophthalmic optics Visual acuity testing Standard and clinical optotypes and
their presentation added as informative reference in the bibliography
— Reference to ISO 7921:2024 Ophthalmic optics and instruments- Near reading charts added as informative
reference in the bibliography
— Reference to ISO 10938:2016 Ophthalmic optics — Chart displays for visual acuity measurement — Printed,
projected and electronic added as informative reference in the bibliography
— Reference to ASTM E3168, Standard practice for Determining Low-Contrast Visual Acuity of Radiographic
Interpreters added as informative reference in the bibliography
— New terms and definitions added
— Charts for Illumination level and Luminance added; Chart for Eye to Chart distance for Near, Far and
Colour vision added
— Additional provisions for vision correction added
— Test instructions for Near, Far, and Colour vision added

iv
ISO/DIS 18490:2025(en)
— Informative information for grey scale perception and low contrast acuity added as Annexes (Annex G
and Annex H)
— For Near vision removed use of Jaeger Chart and Tumbling E and added use of Reading Charts and
Snellen chart
— Acceptance level for Near, Far, Colour visions added
— Examples of Radner, Snellen and Landolt charts added as Annexes
— Corresponding Reading Acuity Notations for Test Distances of 40 cm (16 inches) and 32 cm (12.5 inches)
added as Annex
v
ISO/DIS 18490:2025(en)
Introduction
Standards for NDT Personnel qualification and certification require that the visual acuity of inspection
personnel is verified as being appropriate to their function. By meeting the vision acuity level defined in
this International Standard, such requirements of ISO 9712 will be met. The purpose of this International
Standard is to provide a detailed, standardised procedure for the evaluation of vision acuity for such
personnel under defined lighting conditions.
The tests are not medical in nature and are intended to objectively ensure adequate vision perception
without reliance on reading ability or text identification. Be
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