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Tuesday 17 November, 2009 | RSS Feed

Lens Standards

by James | post a comment

Lens Standards

The Australian Standard for Sunglasses and Fashion Spectacles (AS/NZS 1067:2003) is one of the toughest mandatory sunglass standards in the world. The Standard has recently been reviewed and updated and specifies new labeling requirements for sunglasses and fashion spectacles.
Key points of the Standard are as follows:
Sunglasses and Fashion Spectacles are categorized by the amount of light allowed to pass through the lens.   This is called the luminous transmittance.   A lens with a 22% transmittance allows 22% of the light to pass through to the eye.   The labeling requirements for sunglasses are based on this transmittance value.

Lens Category 0 - 80% - 100% transmittance
Fashion Spectacles - Not Sunglasses
Very low sun glare reduction, some UV protection

Lens Category 1 - 43% - 80% transmittance
Fashion Spectacles - Not Sunglasses
Limited Sunglare reduction, some UV protection

Lens Category 2 - 18% - 43% transmittance
Medium sun glare reduction, good UV protection

Lens Category 3 - 8% - 18% transmittance
High sun glare reduction, good UV protection
Lens Category 4 - 3% - 8% transmittance
Sunglasses - Special Purpose
Very high sun glare reduction, good UV protection

Ultraviolet Protection
UVC - Almost all these harmful rays are blocked out by the earth atmosphere.
UVB - The Standard requires the UVB transmittance to be 5% of the luminous transmission for any given lens. For example, if the luminous transmittance is 20% then the allowed UVB transmittance is 1%. In other words 99% of the harmful UVB rays must be blocked out.
UVA - The Standard has similar requirements for UVA transmittance to UVB transmittance. For Lens Categories 0, 1 and 2, the UVA transmittance must be no more than the luminous transmittance. For Lens Categories 3 and 4 the allowed UVA transmittance is 50% of the luminous transmittance.

Our sunglasses uses only UV400 lenses which exceed the Australian Standard for UV protection.

Sunglass Size
The minimum vertical diameter for adult sunglasses is 28mm and the minimum for children is 24mm. Small framed sunglasses that are sometimes popular overseas are illegal in Australia. They let in more light and UV rays and are considered unsafe in Australian conditions.

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