Overview
EN ISO 10341:2012 - Ophthalmic instruments - Refractor heads (ISO 10341:2012) specifies requirements and test methods for refractor heads (phoropters) used to determine refractive errors and binocular functions of the human eye. This international/CEN-adopted standard defines measuring ranges, optical tolerances, construction and functional criteria, test procedures and manufacturer information needed for safe, accurate and interoperable ophthalmic instruments.
Key topics and technical requirements
- Scope and normative references: Cross-references include ISO 7944 (reference wavelengths), ISO 8429 (graduated dial scale), ISO 13666 (vocabulary), ISO 15004-1 (general ophthalmic instrument requirements) and IEC 60601-1 (medical electrical safety).
- Measuring ranges (per side): spherical 0 to +15 D and 0 to −15 D (0.25 D steps), astigmatic 0 to 5 D (0.25 D steps), cylinder axis 0°–180° (5° steps, estimates to 1°), prism 0 Δ–10 Δ (1 Δ steps or continuous). Combined prismatic power ≥ 30 Δ.
- Optical tolerances: The standard lists tolerances for spherical and cylindrical powers, prismatic power and axis/base settings. Examples include spherical tolerances (e.g., ±0.06 D for 0–3 D) and cylinder tolerances (e.g., 0.06 D for ≤0.50 D). Prismatic tolerances and centration limits are also specified.
- Reference wavelength: Dioptric powers referenced to λ = 546.07 nm (or optionally 587.56 nm) per ISO 7944.
- Construction & function: Minimum lens aperture 16 mm (11 mm allowed for prisms ≥ 6 Δ), built-in Jackson crossed cylinder on each side, occlusion/dissociation device, interpupillary distance adjustable 50–75 mm, forehead rest range ≥ 10 mm, stray light control, positive alignment and centring of lenses.
- Test methods: All tests are type tests. Measurement devices must have uncertainty ≤ 0.01 D or 20% of tolerance (whichever larger) and ≤ 0.5° for axis/base. Annex A gives an example test device.
- Manufacturer information & markings: Required user instructions, disinfection guidance, identification (manufacturer, model, serial number), auxiliary wheel symbol markings (e.g., MR, SS, PH), and reference to ISO 10341 when claiming compliance.
Applications and users
- Intended for ophthalmic instrument manufacturers, quality assurance and test laboratories, clinical engineers, and procurement specialists specifying phoropters/refractor heads.
- Used for design validation, type testing, QA acceptance, regulatory submissions and specifying equipment performance in eye clinics, optometry practices and hospitals.
Related standards
Keywords: EN ISO 10341:2012, ISO 10341:2012, refractor heads, phoropter, ophthalmic instruments, refractive error, binocular functions, test methods, optical tolerances.