BS 2738-1:1989
Superseded
A superseded Standard is one, which is fully replaced by another Standard, which is a new edition of the same Standard.
A superseded Standard is one, which is fully replaced by another Standard, which is a new edition of the same Standard.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
15-11-1998
English
28-02-1989
Foreword
Committees responsible
Specification
1. Scope
2. Definitions
3. Lens power
4. Addition power of all lenses
5. Cylinder axes
6. Lens positioning and optical centration
7. Prismatic power
8. Multifocal lenses
9. Marking
Appendix
A. Recommendations regarding subjective characteristics
of spectacle lenses
Tables
1. Lens power
2. Cylinder axes
3. Base setting of prisms
4. Prismatic power
Figures
1. Positions for determining, by use of a focimeter,
the addition power of a front surface multifocal
or progressive power lens
2. Recommended system for visually inspecting a lens
for defects
3. Front view of round lenses illustrating marks
(exaggerated) on back surfaces denoting right and
left
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