Overview
EN ISO 11979-2:2024 (published by CEN, identical to ISO 11979-2:2024) defines the optical properties and test methods for intraocular lenses (IOLs). The standard covers monofocal, toric, simultaneous vision (SVIOL - including multifocal, extended depth of focus and full visual range designs), and accommodative IOLs. The generic term “IOL” in the document also includes phakic intraocular lenses (PIOL). It supersedes the 2014 edition and adds updated measurement methods, requirements and a new normative optical characterization annex.
Key topics and technical requirements
- Scope and applicability: Specifies requirements and standardized test methods related to IOL optical function rather than surgical or clinical procedures.
- Dioptric power: Defines measurement procedures (Annex A) and specific guidance for toric, simultaneous vision and accommodating designs. Interlaboratory precision figures from the document highlight typical repeatability and reproducibility (approx. 0.5% and 1% for dioptric power).
- Imaging quality (MTF): Uses modulation transfer function (MTF) testing as the primary imaging-quality metric (Annex B). Historical Air Force target-based methods were removed in favor of MTF-based methods.
- Optical characterization: New normative Annex C requires model-specific characterization to assess optical-design risks and to inform preclinical and clinical investigation design.
- Spectral transmittance and UV cut-off: Specifies measurement of spectral transmittance and clarifies UV cut-off wavelength reporting for safety and diagnostic/laser exposure considerations.
- Units and conventions: Adopts millimetre and degree units for linear and angular spatial frequencies in line with ISO 9334. The document removes older resolution-efficiency metrics as MTF methods have become standard.
Practical applications
- Establishing quality control and release criteria for IOL production (power and imaging performance).
- Defining preclinical optical testing protocols for new IOL models, including multifocal/EDOF and accommodating designs.
- Supporting regulatory submissions, conformity assessment and notified-body evaluations in jurisdictions that adopt CEN/ISO standards.
- Guiding test laboratories and manufacturers in interlaboratory reproducibility and method selection (MTF, spectral transmittance).
Who should use this standard
- IOL manufacturers (design, R&D, QC)
- Medical device test laboratories and calibration facilities
- Regulators, notified bodies and conformity assessment organizations
- Clinical researchers planning device performance evaluations
Related standards
- Other parts of the ISO 11979 series (see ISO website for the full list).
- Referenced document for spatial-frequency units: ISO 9334.
For the complete normative text, measurement procedures and annexes consult the official EN ISO 11979-2:2024 / ISO 11979-2:2024 publication available from ISO/CEN.
