SIST EN ISO 18490:2026

Non-destructive testing - Evaluation of vision acuity of NDT personnel (ISO 18490:2026)

This document specifies quality requirements for the chart, test procedure and acceptance level for near, far, and colour vision acuity of NDT personnel. Information for grey scale perception and low contrast can be found in the annexes. This document also specifies the qualification requirements for personnel permitted to carry out the test.
This document is only applicable to vision acuity under defined conditions similar to those encountered during routine NDT inspection. This document does not address an individual’s overall visual acuity and users are advised to consider the need for a general eye examination by specialist medical personnel to ensure general vision acuity.

Zerstörungsfreie Prüfung - Bestimmung der Sehfähigkeit von ZfP-Personal (ISO 18490:2026)

Dieses Dokument legt Qualitätsanforderungen an die Sehtesttafel, Prüfverfahren und Kriterien für die akzeptierbare Nah , Fern- und Farbsehschärfe des Personals für die ZfP fest. Informationen zur Graustufenwahrnehmung und zur Kontrastsehfähigkeit sind in den Anhängen zu finden. Dieses Dokument legt die Anforderungen an die Qualifikation des Personals fest, das zur Durchführung der Prüfung befugt ist.
Dieses Dokument gilt nur für die Sehschärfe unter festgelegten Bedingungen, die den Bedingungen bei einer routinemäßigen zerstörungsfreien Prüfung entsprechen. In diesem Dokument wird die Gesamtsehschärfe einer bestimmten Person nicht behandelt; den Anwendern wird empfohlen zu überlegen, ob eine allgemeine Augenuntersuchung durch spezialisiertes medizinisches Personal notwendig ist, um sicherzustellen, dass die allgemeine Sehschärfe ausreichend ist.

Essais non destructifs - Évaluation de l'acuité visuelle du personnel END (ISO 18490:2026)

Le présent document spécifie les exigences de qualité requises pour le tableau, la procédure de contrôle et le niveau d’acceptation pour l’acuité de la vision de près, de loin et des couleurs du personnel END. Les annexes contiennent des informations sur la perception de l’échelle de gris et des faibles contrastes. Le présent document spécifie également les exigences relatives à la qualification du personnel autorisé à effectuer ces contrôles.
Le présent document ne s'applique qu'à l’acuité visuelle dans des conditions définies, similaires à celles rencontrées lors des contrôles END de routine. Le présent document n’aborde pas l’acuité visuelle générale des individus. Il est conseillé aux utilisateurs d’envisager de procéder à un examen général d’ophtalmologie chez un médecin spécialiste afin de s’assurer que leur acuité visuelle générale.

Neporušitvene preiskave - Vrednotenje ostrine vida za osebje, ki izvaja neporušitvene preiskave (NDT) (ISO 18490:2026)

Ta dokument določa zahteve glede kakovosti za tabelo, postopek preskušanja in raven sprejemljivosti za ostrino vida na blizu, daleč in barvno ostrino vida osebja za NDT (neporušitveno testiranje). Informacije o zaznavanju sivinskih odtenkov in nizkem kontrastu so na voljo v prilogah. Ta dokument prav tako določa zahteve za usposobljenost osebja, ki je pooblaščeno za izvajanje preskusa.
Ta dokument se uporablja samo za ostrino vida pod določenimi pogoji, ki so podobni tistim, s katerimi se srečujemo med rutinskim pregledom NDT. Dokument ne obravnava splošne ostrine vida posameznika, uporabnikom pa svetujemo, da razmislijo o potrebi po splošnem očesnem pregledu pri specialističnem medicinskem osebju, da zagotovijo splošno ostrino vida.

General Information

• Status: Published
• Public Enquiry End Date: 20-Jul-2025
• Publication Date: 27-May-2026
• ICS: 03.100.30 - Management of human resources
• ICS: 11.040.70 - Ophthalmic equipment
• ICS: 19.100 - Non-destructive testing
• Technical Committee: PKG - Testing of metallic materials
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 15-Apr-2026
• Due Date: 20-Jun-2026
• Completion Date: 28-May-2026
• Ref Project: EN ISO 18490:2026 - Non-destructive testing - Evaluation of vision acuity of NDT personnel (ISO 18490:2026)

Relations

• Revises: SIST EN ISO 18490:2015 - Non-destructive Testing - Evaluation of vision acuity of NDT personnel (ISO 18490:2015)
• Effective Date: 13-Dec-2023

Overview

SIST EN ISO 18490:2026 - Non-destructive testing – Evaluation of vision acuity of NDT personnel, establishes internationally recognized requirements for assessing the visual acuity of personnel performing non-destructive testing (NDT). Published by the European Committee for Standardization (CEN) and aligned with ISO, this standard specifies the quality and procedural requirements for testing near, far, and colour vision. It also covers the necessary qualifications for individuals administering the tests and offers guidance on related aspects such as grey scale perception and low-contrast vision, both of which are particularly pertinent in NDT contexts like radiography.

Key Topics

• Testing Requirements
  The standard details minimum quality requirements for charts (e.g., Radner, Snellen, Landolt, and Ishihara charts), test procedures, and acceptance criteria for near, far, and colour vision acuity in NDT personnel.

• Test Procedure and Conditions
  Specific guidelines are provided for the administration of vision tests, including:

  • Proper lighting levels (lux requirements)
  • Specified testing distances for each chart type
  • Use of appropriate eyewear as worn during actual NDT tasks
  • Ensuring charts are produced to a defined standard and correctly marked

• Personnel Qualifications
  The document outlines that testing must be conducted by qualified individuals, such as licensed physicians, optometrists, nurses, ophthalmologists, or designated NDT Level 3 personnel.

• Acceptance Levels
  Clearly defined pass/fail thresholds are given for each vision component. For example:

  • Near vision (Radner or Snellen chart) and far vision (Snellen or Landolt chart) with specific size and acuity notations.
  • Colour vision verification via the first 17 plates of a standard Ishihara chart, with additional employer-administered trade tests for those not meeting criteria.

• Annexes and Informative Content
  Annexes provide further details on alternative charts, grey scale perception, low contrast acuity, and sample documentation.

Applications

SIST EN ISO 18490:2026 is essential for organizations involved in non-destructive testing across industries such as:

• Aerospace
• Energy and power generation
• Manufacturing
• Construction
• Transportation

Ensuring that NDT personnel meet required vision acuity is a vital safety and quality assurance measure. Implementation of this standard helps organizations:

• Maintain compliance with ISO 9712 and other certification/qualification schemes for NDT personnel.
• Demonstrate due diligence regarding the competence of inspection staff.
• Reduce the risk of inspection errors due to inadequate vision, thereby enhancing defect detection, safety, and service reliability.

Regular vision screening as defined by SIST EN ISO 18490:2026 also supports overall workforce health monitoring and compliance with occupational health and safety regulations.

Related Standards

Organizations applying SIST EN ISO 18490:2026 should also consider alignment with the following relevant standards:

• ISO 9712 – Non-destructive testing - Qualification and certification of NDT personnel
• ISO 7921:2024 – Ophthalmic optics and instruments – Near reading charts
• ISO 8596:2017 – Ophthalmic optics - Visual acuity testing - Standard and clinical optotypes and their presentation
• ISO 10938:2016 – Ophthalmic optics - Chart displays for visual acuity measurement - Printed, projected and electronic
• ASTM E3168 – Determining Low-Contrast Visual Acuity of Radiographic Interpreters

By integrating the provisions of SIST EN ISO 18490:2026 into their quality and training systems, NDT organizations can ensure thorough, consistent vision screening and uphold the highest levels of inspection performance and reliability.

Standards Content (Sample)

SLOVENSKI STANDARD
01-julij-2026
Neporušitvene preiskave - Vrednotenje ostrine vida za osebje, ki izvaja
neporušitvene preiskave (NDT) (ISO 18490:2026)
Non-destructive testing - Evaluation of vision acuity of NDT personnel (ISO 18490:2026)
Zerstörungsfreie Prüfung - Bestimmung der Sehfähigkeit von ZfP-Personal (ISO
18490:2026)
Essais non destructifs - Évaluation de l'acuité visuelle du personnel END (ISO
18490:2026)
Ta slovenski standard je istoveten z: EN ISO 18490:2026
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.

EN ISO 18490
EUROPEAN STANDARD
NORME EUROPÉENNE
April 2026
EUROPÄISCHE NORM
ICS 03.100.30; 19.100 Supersedes EN ISO 18490:2015
English Version
Non-destructive testing - Evaluation of vision acuity of
NDT personnel (ISO 18490:2026)
Essais non destructifs - Évaluation de l'acuité visuelle Zerstörungsfreie Prüfung - Bestimmung der
du personnel END (ISO 18490:2026) Sehfähigkeit von ZfP-Personal (ISO 18490:2026)
This European Standard was approved by CEN on 23 March 2026.

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, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2026 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 18490:2026 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 18490:2026) has been prepared by Technical Committee ISO/TC 135 "Non-
destructive testing" in collaboration with Technical Committee CEN/TC 138 “Non-destructive testing”
the secretariat of which is held by AFNOR.
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 October 2026, and conflicting national standards shall
be withdrawn at the latest by October 2026.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 18490:2015.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN website.
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, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the
United Kingdom.
Endorsement notice
The text of ISO 18490:2026 has been approved by CEN as EN ISO 18490:2026 without any modification.

International
Standard
ISO 18490
Second edition
Non-destructive testing —
2026-03
Evaluation of vision acuity of NDT
personnel
Essais non destructifs — Évaluation de l'acuité visuelle du
personnel END
Reference number
ISO 18490:2026(en) © ISO 2026
ISO 18490:2026(en)
© ISO 2026
All rights reserved. Unless otherwise specified, or required in the context of its implementation, 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
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
ISO 18490:2026(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 . 3
8 Test procedure . 3
8.1 General .3
8.2 Eye to chart distance .3
8.3 Vision Correction .3
8.4 Tests .4
8.4.1 General .4
8.4.2 Near and Far Guidance .4
9 Acceptance levels. 5
Annex A (informative) Radner Chart (Not to scale) . 6
Annex B (informative) Snellen Chart (Not to scale) . 7
Annex C (informative) Landolt Chart (Not to scale) . 8
Annex D (informative) Ishihara Chart (Not to Scale) . 9
Annex E (informative) Sample Colour Trade Test Exam . 10
Annex F (informative) Corresponding Reading Acuity Notations for Test Distances of 40 cm
(16 inches) and 32 cm (12.5 inches) .13
Annex G (informative) Grey Scale Perception Testing . 14
Annex H (informative) Low Contrast Visual Acuity .15
Annex I (informative) Verification of Trained Professional .16
Bibliography .18

iii
ISO 18490:2026(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 document 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) CEN/TC 138, Non-
destructive testing, 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;
— updated references;
— 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;
— guidance on verification of trained professional provided and sample attestation form for NDT Vision
Test Report added as Annexes (Annex I);
— information for grey scale perception and low contrast acuity added as Annexes (Annex G and Annex H);
— for near vision, removed use of 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;

iv
ISO 18490:2026(en)
— corresponding Reading Acuity Notations for Test Distances of 40 cm (16 inches) and 32 cm (12,5 inches)
added as Annex.
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
ISO 18490:2026(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 document, such requirements of ISO 9712 will be met. The purpose of this document 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.
Because it is extremely difficult to demonstrate any equivalency in vision tests, this document has been
prepared in order that an international system can be used without any need to demonstrate equivalence
and is the recommended method of determining vision acuity for NDT Personnel.

vi
International Standard ISO 18490:2026(en)
Non-destructive testing — Evaluation of vision acuity of NDT
personnel
1 Scope
This document specifies quality requirements for the chart, test procedure and acceptance level for near,
far, and colour vision acuity of NDT personnel. Information for grey scale perception and low contrast can be
found in the annexes. This document also specifies the qualification requirements for personnel permitted
to carry out the test.
This document is only applicable to vision acuity under defined conditions similar to those encountered
during routine NDT inspection. This document does not address an individual’s overall visual acuity and
users are advised to consider the need for a general eye examination by specialist medical personnel to
ensure general vision acuity.
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 9712, Non-destructive testing — Qualification and certification of NDT personnel
ISO 7921, Ophthalmic optics and instruments- Near reading charts
ISO 8596, Ophthalmic optics — Visual acuity testing — Standard and clinical optotypes and their presentation
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 9712, ISO 7921, ISO 8596 and the
following 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/
3.1
optotype
letters or symbols shown on an eye chart
3.2
eyewear
form of lens or protective transparent material placed or used between the human eye and the work piece
during routine NDT inspection operations
3.3
trade test
test performed by the employer after failure of the Ishihara Colour test to ensure a candidate can distinguish
and differentiate between the colours used in the NDT methods/ techniques concerned as specified by the
employer.
...