wbfashion

It is not necessary to buy expensive fashion sunglasses in order to have an adequate protection against UV rays. Most of the sunglasses currently on the market block a large proportion of UV rays, but not the same amount. Moreover, it is not always possible to establish how much UV rays are blocked by the sunglasses on the basis of lens color or degree of opacity.

A large number of the sunglasses manufacturers comply voluntarily to labeling standards established by the industry. Three of these standards are: the ANSI Z80.3 Standard, published by the par American National Standards Institute, the UV Labeling Program of the Sunglass Association of America, as well as the CSA Z94.5-95 Standard of the Canadian Association as regards the direct selling of sunglasses. Sunglasses which abide to these standards carry a label or sticker indicating the category -- cosmetic, general purpose, specific purpose. Standards set the protection requirements against UV rays for each category.

Cosmetic sunglasses normally have slightly tinted lenses and are advised for places where the sun is not very strong; they block between 0 and 60 percent of visible light and UVA. They must also block between 87.5 and 95 percent of UVB. Cosmetic lenses are not recommended for day driving, unless the precisely indicated by the manufacturer.

General purpose sunglasses must block between 60 and 92 percent of visible light and UVA. They must also block between 95 and 99 percent of UVB. Wearing general purpose sunglasses is intended for situations where brutal sunlight would force to screw up one's eyes. These lenses are suitable for driving.

Specific purpose sunglasses can block as much as 97 percent of visible light. They must also block at least twice more UVA rays than the visible light till a maximum of 98.5 percent. They must block at least 99 percent of UVB. Specific purpose sunglasses are not intended for driving. It may be indicated on the label that they are suitable for long term exposure to direct sunlight.

Advice

Your sunglasses need not be high-tech to be comfortable and practical. Polarized lenses, which reduce the glare caused by reflection, are particularly useful when driving. Neutral and uniform tints are always a good choice. Grey lenses, darkish or greenish, from medium to dark intensity, will filter the major part of the blue light without causing any notable color distortion. All these characteristics are found in a large number of affordable sunglasses.

Good sense commands to wear sunglasses when it is sunny -- as much for personal comfort as to reduce the risks caused by UV rays and blue light.

Publication of the Ministry of Health - Canada
27th January 2000
(revised)

• Light and UV rays
• Eyes and UV rays
• Why wear sunglasses?
• Which sunglasses?

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