Overview
ISO 8980-1:2017 - Ophthalmic optics - Uncut finished spectacle lenses - Part 1: Specifications for single‑vision and multifocal lenses defines the optical and geometrical requirements and the verification methods for uncut finished single‑vision and multifocal spectacle lenses. It sets tolerances and test procedures that manufacturers and laboratories use to ensure lens performance, interchangeability and patient safety.
Key topics and requirements
- Scope & classification: Applies to uncut finished single‑vision, multifocal and power‑variation lenses.
- Reference conditions: Tolerances apply at a reference temperature of 23 °C ± 5 °C and at reference wavelengths per ISO 7944.
- Measurement equipment: Optical characteristics are verified using a focimeter conforming to ISO 8598‑1.
- Back vertex power: Lenses must meet specified tolerances for principal meridian powers and cylindrical power (see clause 5.2.2 and Table 1 for numeric ranges).
- Cylinder axis: Axis direction tolerances depend on cylindrical power (no axis requirement for <0.12 D). Tolerances range from around ±14° for very low cylinder power to ±2° for higher cylinder powers (see Table 2).
- Addition power (multifocals): Tolerance typically ±0.12 D for additions ≤4.00 D and ±0.18 D for >4.00 D (Table 3).
- Prismatic power and prism base setting: Total prism (including thickness reduction) must comply with prismatic tolerances that depend on prism magnitude and the higher principal power S. Horizontal/vertical tolerance expressions use base values (0.25 / 0.37 / 0.50) plus factors proportional to S (see Table 4 and clause 5.2.5).
- Geometrical requirements: Defines nominal, effective and usable sizes. Diameter tolerances: effective size within −1 mm / +2 mm of nominal; usable size ≥ nominal − 2 mm. Lens thickness at the front surface reference point shall not deviate by more than ±0.3 mm.
- Verification methods: Clauses 6.x specify procedures for measuring back vertex power, cylinder axis, prism, addition power, segment size and surface/material inspection.
Applications / Who uses this standard
- Lens manufacturers and production QC teams - to set production tolerances and inspection criteria.
- Optical laboratories and finishers - to verify uncut finished lenses before edging and mounting.
- Regulatory bodies and conformity assessors - to evaluate compliance with ophthalmic optics requirements.
- Eyecare professionals and dispensers - to interpret lens specifications and ensure prescriptions are met.
Related standards
Keywords: ISO 8980-1:2017, ophthalmic optics, uncut finished spectacle lenses, single‑vision lenses, multifocal lenses, tolerances, verification methods, focimeter, prismatic power, back vertex power.
Open preview (PDF)Ophthalmic optics — Uncut finished spectacle lenses — Part 1: Specifications for single-vision and multifocal lenses