ISO 11979-2:2024

Overview - ISO 11979-2:2024 (Intraocular lenses, optical properties and test methods)

ISO 11979-2:2024 defines requirements and reference test methods for the optical properties of intraocular lenses (IOLs), including monofocal, toric, simultaneous vision (SVIOL: e.g., multifocal, extended depth of focus, full visual range), and accommodative optics. The generic term “IOL” in the standard also covers phakic intraocular lenses (PIOL). This third edition updates imaging-quality methods, adds SVIOL categories, and introduces a new normative optical characterization annex.

Key topics and technical requirements

• Scope: Optical properties (dioptric power, imaging quality, spectral transmittance, optical characterization) measured at simulated in situ conditions or corrected to in situ.
• Dioptric power: Tolerance limits for spherical and cylindrical powers are specified (e.g., spherical power tolerances vary with nominal power ranges; see standard for full table). Toric IOLs require a physical axis indicator aligned to the lowest-power meridian (angle ≤ 5.0°).
• Simultaneous vision IOLs (SVIOL): New category with rules for measuring far power and designed addition powers; alternatives use MTF through‑focus response specifications when no distinct additions exist.
• Imaging quality: Modulation Transfer Function (MTF) is the preferred metric; Air‑Force target resolution efficiency has been removed in favor of MTF-based methods.
• Spectral transmittance: Measurement methods and UV cut-off considerations are included to inform transmission and exposure risks (e.g., when using laser diagnostic/treatment sources).
• Optical characterization: New Annex C provides normative tests to inform optical design risks and guide clinical investigation design for lenses introduced after publication.
• Normative annexes:
  • Annex A - Measurement of dioptric power
  • Annex B - Measurement of MTF (imaging quality)
  • Annex C - Optical characterization

Practical applications and users

Who uses ISO 11979-2:2024:

• IOL manufacturers - to define release criteria, determine measurement methods, and demonstrate compliance for product registration.
• Regulatory bodies and notified bodies - to assess preclinical optical performance and consistency.
• Medical device test labs - for standardized MTF, dioptric power, and spectral transmittance testing.
• Clinicians and researchers - to understand objective optical performance metrics reported for IOL models (power accuracy, imaging quality, spectral behavior).

Practical benefits:

• Ensures consistent measurement and comparability of IOL optics across products and labs.
• Guides design verification for advanced optics (toric alignment, multifocal/EDF performance, accommodating behavior).
• Informs clinical study design through optical risk characterization.

Related standards

• ISO 11979-1 - Vocabulary for IOLs
• ISO 11979-4 - Labelling and information for IOLs
• ISO 9334 / ISO 9335 - Optical transfer function definitions and measurement principles

Keywords: ISO 11979-2:2024, intraocular lenses, IOL, optical properties, test methods, dioptric power, MTF, toric IOL, simultaneous vision IOL, spectral transmittance, optical characterization.