BS 2738-1:1998
Superseded
A superseded Standard is one, which is fully replaced by another Standard, which is a new edition of the same Standard.
A superseded Standard is one, which is fully replaced by another Standard, which is a new edition of the same Standard.
Spectacle lenses Specification for tolerances on optical properties of mounted spectacle lenses
Hardcopy , PDF
31-12-2009
English
15-11-1998
Committees responsible
Foreword
1 Scope
2 Normative references
3 Definitions
4 Classification
5 Requirements
6 Permanent marking of progressive power lenses
7 Test methods
Annex A (informative) Recommendations regarding subjective
characteristics of spectacle lenses
Annex B (informative) Method for evaluating progressive power
lens characteristics
Bibliography
Figure 1 Use of a focimeter to measure the addition power
of a front surface multifocal or progressive power lens
Figure 2 Measurement of the addition power
Figure A.1 Recommended system for visually inspecting a lens
for defects
Figure A.2 Front view of round lenses illustrating marks
(exaggerated) on back surfaces denoting right and left
Figure B.1 Measurement of the optical characteristics in the
as-worn position
Tables
1 Tolerances on the back vertex power of single-vision and
multifocal lenses
2 Tolerances on the back vertex power of progressive power
lenses
3 Tolerances on the direction of the cylinder axis
4 Tolerances on the addition power for multifocal and
progressive power lenses
5 Centration tolerances
6 Prism tolerances
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