Overview
ISO 10341:2012 - Ophthalmic instruments - Refractor heads specifies requirements and type test methods for refractor heads used in the determination of refractive errors and binocular functions of the human eye. This third edition updates tolerances and test tables and takes precedence over ISO 15004-1 where differences exist. The standard targets design, optical performance, functional construction, testing and manufacturer information for refractor heads.
Key Topics and Technical Requirements
- Scope and definitions
- Defines a refractor head, reference plane, and reference distance used for measurements.
- Measuring ranges
- Spherical power: 0 D to +15 D and 0 D to −15 D in 0.25 D steps.
- Cylindrical power: 0 D to 5 D in 0.25 D steps (plus/minus cylinder form).
- Cylinder axis and prism base: 0°–180° / 0°–360° indicated in 5° steps; estimates to 1° possible.
- Prism power: 0 Δ to 10 Δ in 1 Δ steps or continuous; combined prismatic powers ≥ 30 Δ.
- Optical tolerances
- Detailed tolerances for spherical power, cylindrical power, prismatic power, axis/base settings, and centration of lens combinations (see Tables 2–7).
- Powers referenced to wavelengths λ = 546.07 nm or alternatively λ = 587.56 nm per ISO 7944.
- Construction & function
- Minimum lens aperture (16 mm; prisms ≥6 Δ may be 11 mm).
- Provision for reference plane indication and reference distance measurement.
- Occlusion/dissociation device, Jackson crossed cylinder on each side, continuous interpupillary distance (50–75 mm), forehead rest travel ≥ 10 mm.
- Design to minimize stray/internal reflections and ensure lens alignment and patient visual field unobstructed.
- Test methods
- All tests are type tests. Measurement device accuracy limits (e.g., ≤ 0.01 D or 20% of tolerance) and axis/prism measurement accuracy (0.5°).
- Annex A gives an example test device for verifying refractor head optical elements.
- Manufacturer information & markings
- Required instructions for use, disinfection guidance, transport statement, and specific auxiliary wheel markings (e.g., MR, PH, RF).
- Permanent identification requirements and reference to ISO 10341:2012 when claiming compliance.
Applications and Who Uses It
- Manufacturers and designers of refractor heads and ophthalmic diagnostic instruments for product development and conformity.
- Test laboratories and quality assurance teams performing type testing and calibration.
- Clinical engineering, procurement and regulatory staff in hospitals and clinics specifying equipment performance.
- Standards committees and compliance auditors referencing optical and safety tolerances.
Related Standards
Keywords: ISO 10341:2012, refractor heads, ophthalmic instruments, refractive error measurement, optical tolerances, test methods, interpupillary distance, prism tolerances.
