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
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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.
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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
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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.
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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.
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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.