Overview
SIST EN ISO 13666:2019 - Ophthalmic optics: Spectacle lenses - Vocabulary standardizes terminology used for spectacle lenses, lens blanks and fitting purposes. It provides an internationally harmonized vocabulary for ophthalmic optics so that manufacturers, laboratories, eye-care professionals and regulators use consistent terms when specifying, testing, designing or documenting spectacle lenses.
This third edition (ISO 13666:2019) supersedes the 2012 edition and reorganizes all terms into Clause 3, with extensive updates to many definitions (including changes to vertex distance, design/reference points, and replacement of “as‑worn corrected dioptric power” by verification power).
Key topics and technical scope
The standard defines terms across the full lens lifecycle and optical descriptors, including:
- Basic optics and visible/optical radiation concepts
- Lenses and dispensing: blanks, finished lenses, reference points, design reference points, fitting terminology
- Lens materials and surfaces (terminology only - fabrication/material/process terms are covered in ISO 9802)
- Classifications by function, form, type and state of manufacture (e.g., single‑vision, multifocal, power‑variation lenses)
- Measurement terminology: dioptric properties, focal and prismatic properties, spherical/astigmatic power terms
- Multifocal / power‑variation descriptors and centration/focal property vocabulary
- Transmittance, reflectance, polarization and coatings terminology (including new spectral and transmittance terms such as ultraviolet, infrared and solar blue‑light transmittance)
- Annex A: spectral weighting functions and spectral distributions (informative)
The document contains an alphabetical index and a bibliography; there are no normative references within ISO 13666 itself.
Practical applications
Use this vocabulary to:
- Ensure consistent specifications and technical documentation between suppliers, labs and eye‑care professionals
- Improve clarity in procurement contracts, product data sheets and regulatory submissions
- Standardize test reports and quality records in lens manufacturing and inspection
- Support training materials, technical manuals and translations across languages and markets
- Facilitate international trade by aligning terminology with EN/ISO nomenclature
Who should use this standard
- Ophthalmic lens manufacturers and laboratories
- Optometrists, dispensing opticians and ophthalmologists involved in lens selection and fitting
- Standards bodies, regulators and conformity assessment bodies
- Product managers, technical writers and educators in vision care and optical engineering
Related standards
Keywords: SIST EN ISO 13666:2019, spectacle lenses vocabulary, ophthalmic optics terminology, lens blanks, verification power, vertex distance, spectacle magnification, multifocal lens terminology.
