ISO 10338-1996 PDF

Full title and description

ISO 10338:1996 — Optics and optical instruments — Contact lenses — Determination of curvature. This International Standard specifies definitions and methods for determining the curvature (radius of curvature and related geometry) of contact lenses for use in manufacturing quality control, testing and product specification.

Abstract

ISO 10338:1996 defines the parameters and measurement methods used to determine the curvature of contact lenses, covering geometry, basic measurement techniques and instrumentation needed to obtain repeatable radius or sagittal-depth values for posterior and anterior lens surfaces. The standard was later incorporated into the ISO 18369 series that consolidates contact-lens measurement methods.

General information

• Status: Withdrawn.
• Publication date: 1996-07 (published 11 July 1996).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 11.040.70 (Optics and optical instruments).
• Edition / version: Edition 1 (1996).
• Number of pages: 15.

Scope

Specifies terminology, lens geometry relationships (radius, chord, sagittal depth), and standardised measurement procedures for determining curvature of contact lenses. The document focuses on methods applicable to rigid and soft contact lenses where curvature and related parameters are required for specification, interchangeability and quality control. ISO 10338:1996 has since been superseded by consolidated measurement-method requirements in the ISO 18369 series for contact lenses.

Key topics and requirements

• Definitions and geometry: radius of curvature, chord diameter, sagittal depth and relationships between these quantities.
• Measurement methods: fronto‑focometer (profilometry), optical comparator and other specified techniques for anterior and posterior surface curvature determination.
• Instrument specification and calibration procedures to achieve repeatability and traceability.
• Test conditions and equilibrating solutions (where applicable) and environmental control for consistent results.
• Reporting format and tolerances for curvature values in product specifications and test reports.

Typical use and users

Used by contact-lens manufacturers, quality-control and metrology laboratories, ophthalmic product test houses, research laboratories and regulatory authorities to specify and verify lens curvature. The standard supported consistent measurement and communication of curvature-related parameters between suppliers, test labs and customers prior to consolidation into the ISO 18369 series.

Related standards

ISO 10338:1996 was incorporated into and superseded by the ISO 18369 series (Ophthalmic optics — Contact lenses — Part 3: Measurement methods). Notable related documents include ISO 18369-3 (2006, later revised 2017) which consolidates measurement methods for radius of curvature, thickness, diameter, power and related tests. Other earlier contact-lens standards (e.g., ISO 10344 and related optics standards) were similarly consolidated into the 18369 series.

Keywords

contact lens, curvature, radius of curvature, sagittal depth, optics, measurement methods, frontofocometer, optical comparator, ISO 10338, ISO 18369

FAQ

Q: What is this standard?

A: ISO 10338:1996 is an ISO International Standard titled "Optics and optical instruments — Contact lenses — Determination of curvature" that defines how to measure contact-lens curvature for specification and testing.

Q: What does it cover?

A: It covers definitions, geometric relationships (radius, chord, sagittal depth), recommended measurement techniques and instrument requirements for determining curvature of contact lenses.

Q: Who typically uses it?

A: Contact-lens manufacturers, metrology and quality labs, ophthalmic test houses, researchers and regulators concerned with lens specification and conformance use the standard (or its successors) to ensure consistent curvature measurement.

Q: Is it current or superseded?

A: ISO 10338:1996 has been withdrawn and its measurement-method content was incorporated into the ISO 18369 series (ISO 18369-3:2006 and later ISO 18369-3:2017). Users should refer to the current ISO 18369-3 edition for up-to-date measurement requirements.

Q: Is it part of a series?

A: Yes — its subject matter is part of the wider contact-lens series now published as ISO 18369 (Ophthalmic optics — Contact lenses), specifically within the measurement-methods part (Part 3).

Q: What are the key keywords?

A: Contact lens, curvature, radius, sagittal depth, measurement methods, frontofocometer, optical comparator, ISO 10338, ISO 18369.