GB/T 10810.2-2025 Uncut finished spectacle lenses - Part 2: Power-variation
1 Scope
This document specifies the requirements, markings and marks for uncut finished power-variation lenses and describes the corresponding test methods.
This document is applicable to uncut finished power-variation lenses.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 26397 Ophthalmic optics - Terminology (GB/T 26397-2011, ISO 13666: 1998, MOD)
GB 45184 Optometry products - Safety technical specifications of components
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB 26397 and GB 45184 and the following apply.
3.1
verification power
lens vertex power that is specially calculated and provided by the manufacturer as a reference value for verification with a focimeter
Note 1: This value is the measured vertex power provided by the manufacturer.
Note 2: The verification power is not necessarily identical to the ordered power. For example, due to (visual) physiological effects, the light passing through the lens during measurement on a focimeter may not be consistent with the light path at the wearing position.
Note 3: If the manufacturer of an uncut or fitted lens only specifies one vertex power, that vertex power shall be the ordered vertex power for verification purposes.
4 Requirements
4.1 Optical performance
4.1.1 General
If the manufacturer states a verification power, measure according to the verification power, and the tolerances shall meet those specified in GB 45184.
4.1.2 Vertex power at primary reference point
When measured using the method specified in 5.2.1, spectacle lenses shall comply with the tolerances on the power of each principal meridian, and with the tolerances on the cylindrical power.
4.1.3 Direction of the cylinder axis
When measured using the method specified in 5.2.2, the tolerance on the direction of the cylinder axis shall meet those specified in GB 45184.
4.1.4 Variation power
When measured using the method specified in 5.2.3, the tolerance on variation power shall comply with those specified in GB 45184.
4.1.5 Prismatic power and prism base setting
When measured using the method specified in 5.2.4, the tolerance on nominal prismatic power measured at the prism reference point shall meet those specified in GB 45184.
The nominal prismatic power shall be decomposed into horizontal and vertical components according to its base setting, and the tolerances on the measured values of each component shall meet those specified in GB 45184.
4.2 Geometric dimensions
4.2.1 Lens sizes
Lens sizes are classified as follows:
a) nominal size (dn): dimension(s), in millimetres, indicated by the manufacturer;
b) effective size (de): actual dimension(s), in millimetres, of the lens;
c) usable size (du): dimension(s), in millimetres, of the area that is optically usable.
When tested using the method specified in 5.3.1, the tolerances on size shall be as follows:
——effective size, de:dn−1mm≤de≤dn+2mm;
——usable size, du:du≥dn−2mm.
The tolerance on usable size does not apply for lenses with a carrier curve, such as lenticulars.
Special custom lenses may be determined by agreement with the producer.
4.2.2 Thickness
When tested using the method specified in 5.3.2, the tolerance between the measured thickness value and the nominal value shall be ±0.3 mm.
4.3 Material and surface quality
When tested using the method specified in 5.4, within the 30 mm diameter area centered on the lens prism reference point, there shall be no various kinds of defects on or inside the lens that may impair vision. Isolated, tiny internal and/or surface defects shall be permitted outside this identified inspection area.
5 Test methods
5.1 Test conditions
The test ambient temperature shall be 23∘C±5∘C.
5.2 Optical performance
5.2.1 Vertex power at primary reference point
Conduct the measurement according to the method described in GB 45184.
5.2.2 Direction of the cylinder axis
Conduct the measurement according to the method described in GB 45184.
5.2.3 Variation power
Conduct the measurement according to the method described in GB 45184.
5.2.4 Prismatic power and prism base setting
Conduct the measurement according to the method described in GB 45184.
5.3 Geometric dimensions
5.3.1 Lens sizes
The measurement shall be performed using a measuring instrument whose minimum dividing value is not greater than 0.1 mm.
5.3.2 Thickness
The measurement shall be performed vertically at the lens prism reference point using a measuring instrument whose minimum dividing value is not greater than 0.05 mm.
5.4 Material and surface quality
Carry out the lens inspection at a light/dark boundary and without the aid of magnifying optics. The recommended system is shown in Figure 1. Inspect the lens in a room with ambient lighting of about 200 lx. Use a light source of at least 400 lm as an inspection lamp, for example, a fluorescent tube of 15 W or a partly shaded 40 W incandescent clear lamp. Other equivalent methods may also be used.
Note: The inspectors shall be trained and have proficiency in operation.
Key
1——matt black background (150 mm×360 mm);
2——light source, ≥400 lm;
3——adjustable opaque shade or mask;
4——range of adjustment;
5——movable spectacle lens;
6——plane of the observer’s eye;
7——unobstructed vision.
Note: The opaque shade or mask is adjusted to shield the eye from the light source and to allow the lens to be illuminated.
Figure 1 System for inspecting a lens material and surface quality
6 Marking
6.1 Permanent marking
The lens shall be permanently marked with at least the following (see Annex B):
a) the alignment reference marking comprising two marks located nominally 34 mm apart, equidistant to a vertical plane through the fitting point or prism reference point;
b) variation power, in the form of a numerical or equivalent marking, marked under the temporal alignment fitting reference marking; power-variation lenses without a secondary reference point should be excluded from this requirement, but if available in more than one variation power, an appropriate indication shall be given;
c) marking of manufacturer or supplier.
6.2 Optional non-permanent marking
Contents
Foreword i
Introduction iv
1 Scope
2 Normative references
3 Terms and definitions
4 Requirements
4.1 Optical performance
4.2 Geometric dimensions
4.3 Material and surface quality
5 Test methods
5.1 Test conditions
5.2 Optical performance
5.3 Geometric dimensions
5.4 Material and surface quality
6 Marking
6.1 Permanent marking
6.2 Optional non-permanent marking
7 Mark
Annex A (Informative) Comparison of clause/subclause numbers between this document and ISO 8980-2: 2017
Annex B (Informative) Schematic diagram of position of each reference point of uncut finished power-variation lenses
GB/T 10810.2-2025 Uncut finished spectacle lenses - Part 2: Power-variation
1 Scope
This document specifies the requirements, markings and marks for uncut finished power-variation lenses and describes the corresponding test methods.
This document is applicable to uncut finished power-variation lenses.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 26397 Ophthalmic optics - Terminology (GB/T 26397-2011, ISO 13666: 1998, MOD)
GB 45184 Optometry products - Safety technical specifications of components
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB 26397 and GB 45184 and the following apply.
3.1
verification power
lens vertex power that is specially calculated and provided by the manufacturer as a reference value for verification with a focimeter
Note 1: This value is the measured vertex power provided by the manufacturer.
Note 2: The verification power is not necessarily identical to the ordered power. For example, due to (visual) physiological effects, the light passing through the lens during measurement on a focimeter may not be consistent with the light path at the wearing position.
Note 3: If the manufacturer of an uncut or fitted lens only specifies one vertex power, that vertex power shall be the ordered vertex power for verification purposes.
4 Requirements
4.1 Optical performance
4.1.1 General
If the manufacturer states a verification power, measure according to the verification power, and the tolerances shall meet those specified in GB 45184.
4.1.2 Vertex power at primary reference point
When measured using the method specified in 5.2.1, spectacle lenses shall comply with the tolerances on the power of each principal meridian, and with the tolerances on the cylindrical power.
4.1.3 Direction of the cylinder axis
When measured using the method specified in 5.2.2, the tolerance on the direction of the cylinder axis shall meet those specified in GB 45184.
4.1.4 Variation power
When measured using the method specified in 5.2.3, the tolerance on variation power shall comply with those specified in GB 45184.
4.1.5 Prismatic power and prism base setting
When measured using the method specified in 5.2.4, the tolerance on nominal prismatic power measured at the prism reference point shall meet those specified in GB 45184.
The nominal prismatic power shall be decomposed into horizontal and vertical components according to its base setting, and the tolerances on the measured values of each component shall meet those specified in GB 45184.
4.2 Geometric dimensions
4.2.1 Lens sizes
Lens sizes are classified as follows:
a) nominal size (dn): dimension(s), in millimetres, indicated by the manufacturer;
b) effective size (de): actual dimension(s), in millimetres, of the lens;
c) usable size (du): dimension(s), in millimetres, of the area that is optically usable.
When tested using the method specified in 5.3.1, the tolerances on size shall be as follows:
——effective size, de:dn−1mm≤de≤dn+2mm;
——usable size, du:du≥dn−2mm.
The tolerance on usable size does not apply for lenses with a carrier curve, such as lenticulars.
Special custom lenses may be determined by agreement with the producer.
4.2.2 Thickness
When tested using the method specified in 5.3.2, the tolerance between the measured thickness value and the nominal value shall be ±0.3 mm.
4.3 Material and surface quality
When tested using the method specified in 5.4, within the 30 mm diameter area centered on the lens prism reference point, there shall be no various kinds of defects on or inside the lens that may impair vision. Isolated, tiny internal and/or surface defects shall be permitted outside this identified inspection area.
5 Test methods
5.1 Test conditions
The test ambient temperature shall be 23∘C±5∘C.
5.2 Optical performance
5.2.1 Vertex power at primary reference point
Conduct the measurement according to the method described in GB 45184.
5.2.2 Direction of the cylinder axis
Conduct the measurement according to the method described in GB 45184.
5.2.3 Variation power
Conduct the measurement according to the method described in GB 45184.
5.2.4 Prismatic power and prism base setting
Conduct the measurement according to the method described in GB 45184.
5.3 Geometric dimensions
5.3.1 Lens sizes
The measurement shall be performed using a measuring instrument whose minimum dividing value is not greater than 0.1 mm.
5.3.2 Thickness
The measurement shall be performed vertically at the lens prism reference point using a measuring instrument whose minimum dividing value is not greater than 0.05 mm.
5.4 Material and surface quality
Carry out the lens inspection at a light/dark boundary and without the aid of magnifying optics. The recommended system is shown in Figure 1. Inspect the lens in a room with ambient lighting of about 200 lx. Use a light source of at least 400 lm as an inspection lamp, for example, a fluorescent tube of 15 W or a partly shaded 40 W incandescent clear lamp. Other equivalent methods may also be used.
Note: The inspectors shall be trained and have proficiency in operation.
Key
1——matt black background (150 mm×360 mm);
2——light source, ≥400 lm;
3——adjustable opaque shade or mask;
4——range of adjustment;
5——movable spectacle lens;
6——plane of the observer’s eye;
7——unobstructed vision.
Note: The opaque shade or mask is adjusted to shield the eye from the light source and to allow the lens to be illuminated.
Figure 1 System for inspecting a lens material and surface quality
6 Marking
6.1 Permanent marking
The lens shall be permanently marked with at least the following (see Annex B):
a) the alignment reference marking comprising two marks located nominally 34 mm apart, equidistant to a vertical plane through the fitting point or prism reference point;
b) variation power, in the form of a numerical or equivalent marking, marked under the temporal alignment fitting reference marking; power-variation lenses without a secondary reference point should be excluded from this requirement, but if available in more than one variation power, an appropriate indication shall be given;
c) marking of manufacturer or supplier.
6.2 Optional non-permanent marking
Contents of GB/T 10810.2-2025
Contents
Foreword i
Introduction iv
1 Scope
2 Normative references
3 Terms and definitions
4 Requirements
4.1 Optical performance
4.2 Geometric dimensions
4.3 Material and surface quality
5 Test methods
5.1 Test conditions
5.2 Optical performance
5.3 Geometric dimensions
5.4 Material and surface quality
6 Marking
6.1 Permanent marking
6.2 Optional non-permanent marking
7 Mark
Annex A (Informative) Comparison of clause/subclause numbers between this document and ISO 8980-2: 2017
Annex B (Informative) Schematic diagram of position of each reference point of uncut finished power-variation lenses
