TS EN ISO 18490

TS EN ISO 18490 is the standard for evaluating the visual acuity of NDT personnel. In non-destructive testing, an operator’s near vision, distance vision and colour discrimination all affect the reliability of inspection results, so this document focuses on how that capability is assessed under defined and repeatable conditions. In general technical terms, visual aptitude in NDT is tied to the ability to resolve fine detail, distinguish contrast differences and correctly read critical indications on samples, displays or images.

What this standard covers for NDT personnel

The standard specifies the quality requirements for the vision chart, the test procedure and the acceptance level. It also sets qualification requirements for personnel permitted to carry out the test. Its scope is limited to vision acuity evaluated under defined conditions similar to those encountered during routine NDT inspection. In practice, this provides a controlled framework for judging whether an inspector’s vision is suitable for the work environment, while not replacing a full medical eye examination of an individual’s overall visual health.

Why near, far, colour and low-contrast vision matter

In NDT, visual performance is more than the ability to read text. Near vision matters in close-up examinations and short-distance reading; distance vision is relevant when assessing indicators or images viewed from farther away; and colour vision supports correct interpretation of colour coding, surface markings and some display systems. The standard also notes that information on grey scale perception and low contrast can be found in the annexes. This distinction is important because some indications are visible mainly through subtle tonal or brightness differences, and those conditions can place different demands on the eye than general everyday vision.