UV Protection Standards:
Several regulatory agencies have set standards for UV protection. The most widely recognized are ANSI (The American National Standards Institute), CSA (Canadian Standards Association), CEN (European standard), BSI (British Standard) and AS (Australian Standard).
ANSI is one of two U.S. organizations to set standards and labeling for sunglasses. The other is the Sunglass Association of America in conjunction with the U.S. Food
& Drug Administration (FDA). Both standards and labeling programs are voluntary.
ANSI sets requirements for cosmetic quality, refractive properties (e.g., distortion or blur) and impact resistance. ANSI standard Z80.3-1996 divides sunglasses into three groups:
1. cosmetic: sunglasses that block at least 70% of UVB and up to 60% UVA
2. general purpose: sunglasses that block at least 95% of UVB and a minimum of 60% UVA
3. special purpose: sunglasses that block at least 99% of UVB and 60% UVA
In the USA, unless sunglasses meet standards of the International Standards Organization (ISO-14889) or ANSI Z80.3-1996 section 4.6.3, they must carry a caution that reads: "not recommended for use while driving."
The Canadian standard for non-prescription sunglasses is similar to the ANSI standard. This standard also provides guidelines for color transmission
, has special requirements for different kind of lenses (e.g., polarizing to photosensitive) and tests for impact resistance.
- Cosmetic sunglasses have lightly tinted lenses for use in sunlight that is not harsh. They block from 0 to 60 percent of visible light and UV-A rays and between 87.5 and 95 percent of UV-B rays. These glasses are not usually recommended for daylight driving
- General purpose sunglasses block from 60 to 92 percent of visible light and UV-A rays and between 95 and 99 percent of UV-B rays. These sunglasses are good for driving, and are recommended whenever sunlight is harsh enough to make you squint
- Special purpose sunglasses block up to 97 percent of visible light and up to 98.5 percent of UV-A rays. They also block at least 99 percent of UV-B rays, and are suitable for prolonged sun exposure. These sunglasses are not recommended for driving
European standards classify sunglasses into four groups based on their ability to block UV rays: weak, medium, strong and intense. Sunglasses in the latter group are not recommended for driving.
British standards are similar to but slightly more stringent than European or American standards for UV blockage.
AS 1067.1-1990 & 1067.2-1990
Sunglasses that do not met Australian Standards (AS) 1067.1-1990 and 1067.2-1990 cannot be sold in Australia
. Like ANSI and other standards, they ensure that sunglasses provide adequate UV protection and identify lenses that interfere with the ability to recognize the colors of traffic lights or other roadway signals.
Category 2 - 18% - 43% Transmittance - Medium sun glare reduction, good UV protection
Cat. 3 - 8% - 18% Transmittance - High sun glare reduction, good UV protection
Cat. 4 - 3% - 8% Transmittance (Special Purpose) Very high sun glare reduction, good UV protection - MUST NOT BE USED WHEN DRIVING
Contact lenses have not yet been proven to block UV rays. If you wear contacts use sunglasses as well.
Polarized lenses minimize the sun's direct and reflected glare from smooth surfaces like pavement or water
. Polarization, however, has nothing to do with UV protection.
Check the lenses for surface distortion.
Anti-reflective (AR) coating can reduce glare, reflections and ghost images
(unless the ghost is real).
Tint doesnít really matter when it comes to UV blockage. Darker-tinted sunglasses don't block more UV rays than lighter-colored lenses. Tints can help light sensitivity and cosmetically help to add color to your face plus hide wrinkles and dark circles under the eyes.
Gray prevents distortion so that colors remain true.
Green allows high levels of green-yellow light waves, the ones to which the eye is most responsive.
Yellow or Pink lenses help for hazy days and at dusk
Brown and brown-amber absorb blue light waves, which are refracted on hazy days to improve contrast and reduce glare.
Orange seems to work
for brighter days.
Cool Blue and Warm Yellow are mostly for fun although some yellow tints enhance contrast. Scientists disagree on whether blue light poses a risk to the eye, but this is not a high-priority concern for cruisers, since the greatest exposure to blue light comes from snow reflection.