Overview
ISO 10343:2014 specifies requirements and test methods for continuously or digitally indicating ophthalmometers used to measure the radii of curvature and principal meridians of the corneal front surface and contact lenses. The standard assumes local corneal and contact-lens surfaces are spherical or toroidal and takes precedence over ISO 15004-1 where differences exist. It covers instrument performance, optical checks, test devices, documentation, and marking for compliance.
Key topics and requirements
- Measurement scope: Radii of curvature and principal meridians for human corneas and, for higher-resolution instruments, contact lenses (ISO 18369-3).
- Measuring range: 6.5 mm to 9.4 mm (52.0 KD to 36.0 KD).
- Instrument types:
- Type B (corneas only): continuous scale interval 0.1 mm (0.25 KD); digital increment 0.02 mm (0.125 KD); measurement accuracy ±0.05 mm (2σ).
- Type A (corneas + contact lenses): continuous scale interval 0.02 mm (0.125 KD); digital increment 0.02 mm (0.125 KD); measurement accuracy ±0.025 mm (2σ).
- Principal meridian (axis) measurement:
- Range 0°–180°; continuous scale interval 5°; digital increment 1°.
- Accuracy: ±4° for meridional radius differences ≤ 0.3 mm; ±2° for differences > 0.3 mm (2σ).
- Angular indications conform to ISO 8429.
- Eyepiece adjustment: Distance-dependent instruments: dioptric range at least −4 D to +4 D, calibrated −3 D to +2 D.
- Test methods and metrology:
- Type tests using high-precision spherical test surfaces (uncertainty ≤1 μm; local departure ≤0.5 μm; roughness ≤0.05 μm; effective diameter ≥6 mm).
- Meridian axis checks using toric test devices (Type 1 and Type 2) mounted in multiple orientations; see Annex A for configurations.
- Documentation & labeling: Instructions for use, disinfection guidance, manufacturer details, model/serial/type, and a reference to ISO 10343:2014 if claiming conformity. Compliance with IEC 60601-1 and ISO 15004-1 where applicable.
Applications and users
- Manufacturers and designers of ophthalmometers and keratometers (keratometry equipment).
- Contact lens manufacturers and test labs verifying lens curvature (Type A instruments).
- Clinical procurement teams, ophthalmic clinics and optometry practices requiring instrument performance specifications.
- Calibration and conformity assessment laboratories executing type tests and validation against ISO 10343:2014.
- Regulatory bodies and technical assessors evaluating device labeling, safety (IEC 60601-1), and documentation.
Related standards
- ISO 15004-1 - general ophthalmic instrument requirements
- ISO 18369-3 - contact lens measurement methods
- ISO 8429 - graduated dial scale for ophthalmic optics
- IEC 60601-1 - medical electrical equipment safety
Keywords: ISO 10343:2014, ophthalmometer, ophthalmic instruments, keratometry, corneal curvature measurement, contact lens radius, toroidal surface, calibration, measurement accuracy.
