Overview
ISO 12867:2010 specifies minimum requirements and test methods for trial frames used in ophthalmic assessments. Together with ISO 15004‑1, it defines how trial frames should hold trial case lenses (ISO 9801) in front of a subject’s eyes to assess visual acuity and facilitate optical correction. The standard applies to headband-mounted, bracket-mounted and spectacle‑style trial frames, including half‑eye and rotating lens holders, and takes precedence over ISO 15004‑1 where differences exist.
Key topics and technical requirements
- Lens holder design
- Each lens holder must retain a combination of at least three lenses, each in separate compartments along the optical axis.
- Lens axes must be parallel within 2.5° and coincide within a 1 mm tolerance circle when ISO 9801 trial lenses are fitted.
- Lateral/axial lens movement limited to ±0.2 mm from centre.
- Interpupillary distance (IPD)
- Adjustable IPD ranges specified: 55–75 mm (full/reduced aperture) and 59–67 mm (half‑eye).
- Optical alignment and rotation
- Lens rotation of at least 180° per lens.
- Geometrical axes of lens holders must be parallel within 2° and relative axial displacement ≤ 0.5 mm.
- Axis scale indicating cylinder axis and prism base must extend to ≥180° with divisions ≤ 5°, increasing anticlockwise per ISO 8429.
- Mechanical and material requirements
- Vertex distance and lens height adjustable via the bridge piece.
- No hazardous sharp edges; materials in contact with skin must be non‑toxic, non‑allergenic and non‑corrosive (or appropriately treated).
- Marking and documentation
- Frames must be permanently marked with manufacturer/supplier name and supplied with instructions for use, including disinfection and model identification.
- Test methods
- Type tests for parallelism and alignment; Annex A gives examples using an autocollimation telescope or laser methods.
Applications and users
ISO 12867:2010 is essential for:
- Manufacturers and designers of trial frames to ensure compliant mechanical and optical specifications.
- Quality assurance and testing labs performing type tests and acceptance checks.
- Optometrists and ophthalmologists selecting and using trial frames for refraction and clinical assessments.
- Procurement and regulatory bodies evaluating conformity for clinical equipment purchasing and certification.
- Repair and maintenance services, which must follow disinfection and safety guidance.
Related standards
Keywords: ISO 12867:2010, trial frames, ophthalmic instruments, trial case lenses, interpupillary distance, lens holders, ISO 9801, trial frame testing.
