Overview
EN ISO 10942:2022 / ISO 10942:2022 specifies minimum requirements and test methods for hand‑held direct ophthalmoscopes, a category of ophthalmic instruments used for direct observation of the eye fundus. Published as a third edition and endorsed by CEN, this standard works together with ISO 15004‑1 and ISO 15004‑2 (light‑hazard protection) and takes precedence where conflicts occur. It replaces EN ISO 10942:2006 and sets performance, optical, construction and safety expectations for manufacturers, testing laboratories and regulatory reviewers.
Key topics and technical requirements
- Classification: Two groups - Group A (full requirements) and Group B (reduced requirements).
- Optical performance: Specifies viewing lens power steps and field requirements. Examples include:
- Field of view: ≥ 3° (Group A), ≥ 2.5° (Group B).
- Field of illumination at maximum aperture: ≥ 9° (Group A), ≥ 7° (Group B).
- Viewing system diameter: ≥ 3 mm (Group A), ≥ 2.5 mm (Group B).
- Viewing lenses and controls: Indexed lens disc with directional color coding (positive in black/green, negative in red) and indexing stops; left‑ and right‑hand operation required.
- Illumination system: Defocused beam must be homogeneous and achromatic. Group A requires luminous flux adjustable from maximum down to 10% of maximum, at least two aperture stops (full and reduced) and a red‑free filter; additional filters/graticules optional.
- Optical accuracy and centration: Tolerances for combined refractive power and lens centration are specified (tighter tolerances at low powers, larger at high powers); see the standard for the full table of values.
- Safety - optical radiation hazard: Direct ophthalmoscopes must meet requirements in ISO 15004‑2 (replaces certain clauses of IEC 60601‑1).
- Test methods: Type tests only. Measurement devices must have accuracy better than 10% of the smallest value measured. Example methods: refractive power measured with a focimeter (ISO 8598‑1); field of view measured with the instrument back surface 12 mm from a pin‑hole light source.
Applications and users
Who uses EN ISO 10942:2022:
- Ophthalmic instrument manufacturers (design, production QA, conformity).
- Independent test laboratories and notified bodies (type testing).
- Clinical engineers and service technicians (verification and maintenance).
- Regulatory and procurement teams evaluating device compliance and safety.
Practical uses: product specification, performance verification, lab test protocols, risk/safety assessment (light hazards), and labeling/marking guidance.
Related standards
- ISO 15004‑1 - General requirements for ophthalmic instruments
- ISO 15004‑2 - Light hazard protection for ophthalmic instruments
- IEC 60601‑1 - Medical electrical equipment (referenced)
- ISO 8598‑1 - Focimeter specification for refractive power measurements
For implementation, consult the full EN ISO 10942:2022 text for complete tables, test procedures and marking requirements.
