Popular Woodworking 2006-04 № 154, страница 66

DeWalt Reinforcer Rx

MSA Safety Works Bifocals ^

($20)

Aero Readers

($15 - $20)

If you wear prescription glasses, you probably think your only choices are to wear a pair of safety glasses designed to cover your existing prescription glasses (which can be uncomfortable and distorting), or to shell out some serious cash to buy prescription safety glasses.

Well, the truth is we still aren't impressed with the over-the-glasses option. They are still too bulky. But we did discover something that caused a good deal of excitement from the "visually challenged" on our staff. You can order a pair of prescription safety glasses that

TESTING STANDARDS

Safety glasses have to meet certain construction standards before they can be sold, right? Wrong.

The most current eye safety standards (ANSI Z87.1-2003) were actually written by the American Society of Safety Engineers (ASSE). ANSI (the American National Standards Institute), the group most usually assumed to "control" standards serves as an accrediting body for those standards. OSHA (the Occupational Safety and Health Administration) governs and enforces safety standards in the workplace requiring safety equipment meeting ANSI standards.

Manufacturers of safety glasses aren't required to build glasses to ANSI standards, though most do. When safety glasses meet ANSI standards the manufacturers will imprint a Z87 on the glasses. But what are the standards? Let's take a look at some.

■ HIGH MASS IMPACT: The eyeglasses frame has to be capable of resisting an impact from a pointed projectile weighing 500 grams (17.6 oz.) dropped from a height of 50".

■ HIGH VELOCITY IMPACT: The lenses must be capable of resisting impact from a V4"-diameter steel ball traveling at a velocity of 150 feet per second without any failure.

■ DROP-BALL IMPACT: Both frames and lenses need to resist the impact of a 1"-diameter steel ball dropped from 50".

■ PENETRATION TEST: Lenses must be capable of resisting penetration from a projectile weighing 44.2 grams (1.56 oz.) dropped from a height of 50".

Other ANSI standards cover the prismatic, refractive and hazing properties of the lenses as well as the optical quality itself. All of these can cause image distortion that could create an unsafe working situation. — DT

Aging is a reality for all of us and when reading glasses are necessary we shouldn't use that as an excuse to not be safe. Bifocal lenses are available in magnification strengths from +1.00 to +3.00 and still offer comfort, style and safety.

One of the visibility tests is for peripheral obstruction. A pair of glasses are placed on the mannequin and a light shown from behind. The hood shows where the light is obscured by the glasses, giving an indication of how vision would be obscured.

The magic marker freckles on this fellow are actually indicators of the parts of the head and face that need to be covered by the safety glasses to meet ANSI standards. Canadian and United States standards have been slightly different but are moving toward common ground.

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