Protecting the eyes
January 1, 2007
Every day an estimated 1,000 eye injuries occur in American workplaces. Workers not wearing eye protection and wearing the wrong kind of eye protection are the primary causes of such injuries. The Bureau of Labor Statistics reports that nearly three out of every five injuries are due to workers not wearing eye protection at all.
Workers should always wear eye protection that meets ANSI standard Z87.1-2003 (Z87+), and the eyewear must be properly fitted. Having a good understanding of the various types of eye protection products available can go a long way towards preventing injuries.
Let’s take a look at some of the options prevalent today.
Eye & face protection solutionsSafety glasses with polycarbonate lenses. These are by far the leading choice for eye protection against flying debris, and they also offer protection from ultraviolet (UV) light exposure. A properly designed and tested polycarbonate safety glass complies with ANSI Z87 requirements for impact velocity, mass impact, lens thickness, lens distortion and light transmission. Polycarbonate safety glasses provide an excellent combination of impact resistance and optics. When properly designed, they are lightweight, comfortable and stylish, and can be economical.
Polycarbonate’s impact resistance is the reason why it is used in “bulletproof” windows and in other applications requiring flexibility and strength. One might expect a material that is as strong as polycarbonate to also be very strong in other respects, such as scratch resistance. Polycarbonate gains its strength from being flexible instead of rigid. Because of this, polycarbonate lenses are prone to scratching, and therefore should require a hard coating, especially in dirty environments.
Stylish wraparound safety glasses. The OSHA regulation for eye and face protection, 29 CFR 1910.133, states that “employer shall ensure that each affected employee use eye protection that provides side protection when there is a hazard from flying objects.” A properly designed wraparound style safety glass will meet this standard.
One of the leading innovations in recent years has been the introduction of wraparound safety glasses with style. Although style is not the first thing that comes to mind in industry, style is what motivates many workers to wear their glasses and to wear them throughout the workday. As a result, many companies have embraced this trend in the interest of safety. Companies that choose a selection of close-fitting stylish glasses find that compliance problems drop significantly as workers actually want to wear their safety glasses.
Bifocal safety glasses. A demographic trend has been the aging of our nation’s workforce. As workers pass the age of 40, many require reading glasses. Today’s reading safety glasses made of polycarbonate lenses give workers the ability to read prints and manuals, do close-up work, and do so in a safe and cost-effective way. Companies are increasingly making safety bifocals available to their workforce at a fraction of the cost of prescription safety glasses.
Bifocal safety glasses have become a big market. Innovative designs incorporate bifocal lenses into a stylish, lightweight, comfortable pair of glasses. Other features can include contemporary wraparound frames, soft rubber nose bridge, rubber-tipped temples and, most importantly, ANSI Z87+ compliance. Eye strength varies from worker to worker, so models typically are available in a choice of bifocal powers (diopters). For outdoor construction workers, these glasses are available in gray (sunglass) lenses.
Safety sunglasses. Quality safety sunglass models have NCB (natural color balance) gray lenses to provide protection against bright visible light, UV light, as well as blue light, and infrared protection (IR). Due to changes in the atmosphere, ultraviolet levels are much higher than in the past, making ultraviolet protection for eyes more important than ever. Outdoor workers can be at risk, especially when employed at high altitude jobsites.
Although UV and IR light are invisible to the human eye, it nonetheless can have dangerous effects. UV light can damage the eyes in several ways. Excessive exposure to the lowest wavelengths of UV light, also called UV-C (180-290 nm), can cause damage to the cornea as well as the lens. These wavelengths are present in some industrial environments, such as electric arc welding. Mid UV light is present in sunlight, and these mid wavelengths (UV-B, 290-320 nm) can cause damage to the eyes’ lens as well as cause welders eye. High UV wavelengths (UV-A, 320-380 nm) are present in all outdoor environments; excessive exposure can cause fatigue or snow blindness. Blue light (380-480 nm), present in regular sunlight as well as in office environments due to computer screens, can cause damage to the retina.
Polarized safety glasses. While normal sunglasses decrease the intensity of all light by a uniform percentage, polarized sunglasses selectively eliminate the light coming from a reflective surface. When the sun shines at the sea or any other reflective or partially reflective surface, the reflected light becomes polarized. Typical examples occur when working near water, glass or metal buildings, or around construction vehicles. Whenever reflections are incoming off natural or man-made surfaces, polarized glasses can be a wise choice for protective eyewear. Polarized lenses allow only light in one plane to pass through the lens. Therefore much of the glare can be eliminated. Polarized glasses will not help if you are looking directly at the sun or light source, however they benefit the wearer when the reflected light is at an angle between 30 and 60 degrees.
Over specs safety glasses. Over specs are designed specifically to fit over prescription glasses. This style is “frame free” and has a flatter lens curvature to minimize reflection that tends to occur when dual spectacles are worn. Temples should offer adjustment for both length and angle so they fit over most size prescription glasses.
Goggles. Goggles are often worn when using high-speed power tools such as table saws, drills and chainsaws to prevent flying particles from damaging the eyes. They are also recommended when working in areas where chemical splashing can occur. The ANSI standard covering goggles is ANSI Z87+, so be sure that goggles are rated for this standard and have supporting test reports.
Electric arc protection. Electrical workers can risk exposure to a sudden release of energy that occurs during an electrical arc. The NFPA 70E-2000 standard establishes hazard or risk categories for face protection. Certain arc-shields are suitable for use in hazard/risk categories 1 and 2. The minimum Arc Thermal Performance Value (ATPV) has been established to be 5 cal/cm_ and 8 cal/cm_ for these two risk categories.
In closing, when selecting eye and face protection equipment, be sure not only to choose the right type of equipment for a specific application, but also pay close attention to fit and function. The right equipment poorly fitted is a significant cause of eye injuries.