1 Scope
This standard specifies the requirements, test methods, inspection rules and marking, packing, transport and storage for plano power lenses with uniform optical density.
This standard is applicable to light attenuating sunglass, light-colored sunglasses and the sunglasses for special purpose (skiing, beaching, or mountain climbing etc.), and is not applicable to lenses used for eye protection against artificial light source radiation or lenses correcting visions.
2 Normative References
The following standards contain provisions which, through reference in this text, constitute provisions of this standard. At time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below.GB/T 2828-87 "In-batch Inspection Computation Sampling Procedure and Sampling Table (Applicable to In-batch Inspection)"
GB 2829-87 “Sampling Procedures and Tables for Periodic Inspection by Attributes (Apply to Inspection of Stability for Productive Process)”
GB 10810-1996 "Spectacle Lenses"
GB 13511-92 "Assembled Spectacles"
GB/T 14214-93 "Spectacle Frames"
3 Terms
3.1 Optical density
Optical density is the logarithm to the base 10 of the reciprocal of transmittance, namely, optical density = lg(1/τ).
3.2 Vertex power
See GB 10810.
3.3 Transmittance properties
3.3.1 Luminous transmittance
Luminous transmittance is the ratio of transmitted flux to incident flux. The mathematical expression of luminous transmittance of spectacle lens is as follows:
