2.7 Standards Requirements for Spectacle Lenses
Description
This article is from the Vision and Eye Care FAQ, by grants@research.canon.com.au (Grant Sayer) with numerous contributions by others.
2.7 Standards Requirements for Spectacle Lenses
International and local standards define the properties of lenses that
are required for spectacle lenses. There are different standards for
prescription spectacle lenses and sunglass or fashion lenses.
In the USA the standards include -
-U.S. Sunglass standard for durability is Ct. SGSTD40 (I think)
-U.S. Standard for tints and UV requirements ANSI Z80.3
You can search the ANSI Standards from the WEB using the ANSI homepage
URL: http://www.ansi.org
The standard information is located at the ANSI site as well as other
useful information on opththalmic and optometric standards
.
+ Prescription Lenses
+ Sunglass lenses
The requirements will include some or all of the following attributes
+ surface finish
+ visual quality
+ flame propagation
+ dimensions
+ refractive power of lens
+ prismatic power of lens
+ lens curvature
+ thermal stability
+ optical transmission (UV, visible and near Infra-Red)
+ uniformity of colour
+ colouration limits (red factor, violet factor)
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