PD ISO TR 11797-2024 PDF

Full title and description

STB PD ISO TR 11797-2024 — Ophthalmic optics – Spectacle lenses – Power and prism measurements. This technical report summarizes current measurement methods and tolerance practices for spectacle-lens focal power and describes methods for measuring prism imbalance (relative prism error) between lenses of a mounted pair, with discussion of survey results and possible future approaches.

Abstract

This technical report describes methods currently used to apply tolerances to the focal powers of spectacle lenses, explores methods that could be adopted in the future, and describes methods for measuring prism imbalance between lenses in a mounted pair. It also discusses results from industry surveys (including a 2014 manufacturing-capability survey and a 2018 international web survey) and considers possible new approaches to tolerance application for focal power.

General information

• Status: Published.
• Publication date: 6 November 2024 (ISO listing: 2024-11).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 11.040.70 (Ophthalmic equipment / ophthalmic optics).
• Edition / version: Edition 1 (2024).
• Number of pages: 50 pages (ISO listing).

Scope

ISO TR 11797:2024 surveys and documents current measurement and tolerance methods for spectacle-lens focal power and prism, outlines procedures for assessing prism imbalance in mounted lens pairs, and evaluates alternative tolerance application methods that could be considered for future adoption by industry and standards bodies. The report is informative and intended to support uniform measurement practice and to inform future standardization work in ophthalmic optics.

Key topics and requirements

• Overview of existing methods for measuring spectacle-lens focal power and prism imbalance.
• Discussion of tolerance application practices for focal power and proposals for alternative tolerance schemes.
• Measurement procedures and considerations for relative prism error (prism imbalance) between mounted lenses.
• Summary of industry survey results (manufacturing capability and international responses) informing tolerance practice.
• Recommendations and considerations for future standardization or measurement-method adoption.

Typical use and users

Primary users include spectacle-lens manufacturers, optical metrology and testing laboratories, opticians and dispensing professionals, certification and conformity-assessment bodies, national standards organizations, and members of ISO/TC 172/SC 7 and related technical committees. The report is used to harmonize measurement practice, inform internal quality-control procedures, guide laboratory test methods, and support development or revision of normative standards.

Related standards

ISO TR 11797:2024 is related to other ophthalmic-optics standards addressing uncut and mounted spectacle lenses, coatings, fundamental requirements and test methods. Relevant documents include the ISO 8980 series (uncut finished spectacle lenses and test methods), ISO 21987 (mounted spectacle lenses), ISO 14889 (fundamental requirements for uncut finished lenses), and other TC 172/SC 7 outputs such as ISO/TS 24348 (nickel release / wear simulation) and colorimetry standards used in optical measurement. These documents collectively cover specifications, test methods and performance criteria for spectacle lenses and associated measurements.

Keywords

spectacle lenses, ophthalmic optics, focal power, prism imbalance, prism measurement, lens power tolerances, measurement methods, optical metrology, ISO/TC 172/SC 7.

FAQ

Q: What is this standard?

A: ISO TR 11797:2024 is a technical report titled "Ophthalmic optics – Spectacle lenses – Power and prism measurements" that documents current measurement methods and tolerance practices for spectacle-lens power and prism, and discusses possible future methods.

Q: What does it cover?

A: It covers methods for applying tolerances to spectacle-lens focal power, measurement techniques for prism imbalance between mounted lenses, results from industry surveys (e.g., manufacturing capability and international survey responses), and considerations for potential new tolerance approaches. The report is informative rather than prescriptive.

Q: Who typically uses it?

A: Manufacturers, test laboratories, opticians, conformity-assessment and regulatory bodies, and standards committees use the report to align measurement practice, support quality control, and inform revisions to normative standards.

Q: Is it current or superseded?

A: It is current and published in 2024 (publication date listed as 6 November 2024); it is an ISO technical report (Edition 1, 2024) and is not superseded as of its publication. Users should check for later revisions or related normative standards that may follow.

Q: Is it part of a series?

A: The report relates to the broader body of ophthalmic-optics standards maintained by ISO/TC 172/SC 7 (for example, the ISO 8980 series for uncut finished spectacle lenses, ISO 21987 for mounted spectacle lenses, and ISO 14889 for fundamental lens requirements). It complements those normative standards by surveying measurement and tolerance practices.

Q: What are the key keywords?

A: spectacle lens power, prism measurement, prism imbalance, focal-power tolerances, optical measurement, ophthalmic optics, ISO technical report.