Overview
ISO 11380:1994 is an international standard established by the International Organization for Standardization (ISO) that specifies the essential characteristics and requirements for formers used in edging machines for ophthalmic lenses. These formers shape lenses to fit precisely into spectacle frames. The standard ensures consistency, reliability, and quality in the production of eyewear lenses by defining dimensions, tolerances, materials, and marking requirements for formers.
This standard is critical for manufacturers and suppliers in the ophthalmic optics industry, helping to standardize the tooling used during lens edging and enabling compatibility across different equipment and frames. It does not cover special formers used for secondary treatments such as faceting.
Key Topics
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Scope and Application
ISO 11380:1994 applies specifically to formers utilized in lens edging machines intended to produce spectacle lenses that fit into frames. It excludes formers for additional lens treatments.
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Former Types
Formers are classified based on either:
- The dimensions and shape of the lens to be cut (glass dimension system)
- The dimensions of the spectacle frame opening (frame opening system)
The standard recognizes two systems for identifying and designing formers and recommends stable material selection to maintain dimensional integrity.
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Dimensional Requirements
The standard outlines precise dimensional tolerances - for example, no two formers of nominally identical size and shape should differ by more than 0.2 mm in any circumferential measurement. This ensures a perfect lens fit in the frame without gaps visible with normal corrected vision.
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Markings and Identification
Clear marking on formers is mandatory to include:
- Manufacturer or supplier identification
- Model identification
- Nasal side indicator (letter N with a symbol)
- Horizontal dimension of the lens or the opening (depending on former type), in millimeters
- Optional axis indicators for horizontal and vertical alignment (with a tolerance of ±1 degree)
Markings must be placed as per the standard’s recommendations to ensure easy recognition and traceability.
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Materials and Thickness
The standard specifies the use of materials and thicknesses that guarantee dimensional stability, contributing to consistent lens edging quality.
Applications
ISO 11380:1994 formers play an essential role in the eyewear manufacturing industry, particularly in:
- Lens edging processes - providing standardized shapes and dimensions to cut lenses accurately and fit spectacle frames securely.
- Quality assurance - enabling manufacturers to maintain consistent optical and mechanical performance through tightly controlled tooling specifications.
- Compatibility across equipment - ensuring formers from different suppliers can be used interchangeably on edging machines, supporting workflow efficiency.
- Customization and variety - accommodating different lens sizes and frame types through classification by lens or frame dimensions.
Adopting this standard helps optical labs, lens manufacturers, and frame producers optimize production, reduce waste from ill-fitting lenses, and meet international quality standards in ophthalmic optics.
Related Standards
For comprehensive ophthalmic optics manufacturing and quality control, ISO 11380:1994 relates closely to other ISO standards, such as:
- ISO 8980 series - Optical lenses specifications for spectacle lenses
- ISO 12870 - Ophthalmic optics - Spectacle frames - Requirements and test methods
- ISO 21987 - Ophthalmic optics - Mounted spectacle lenses - Vocabulary and measurable parameters
These complementary standards collaboratively ensure holistic quality in the design, production, and testing of optical instruments and eyewear components.
By adhering to ISO 11380:1994, optical manufacturers ensure precision and quality in lens edging operations, facilitating superior spectacle fitting and enhancing wearer comfort. This standard is fundamental for anyone involved in the design or production of ophthalmic lenses and spectacle frames.
