Choose lens tints that boost visual acuity
Sunglasses have long set a standard in fashion, contributing to the appeal of countless movie icons. From the aviator glasses made famous by Tom Cruise in “Top Gun,” to the bold, gold-rimmed style worn by Elvis, the right pair of shades can add instant swagger to anyone’s look. The importance of style shouldn’t be overlooked in the workplace, either. In fact, style can drive safety eyewear compliance: when workers feel good about how they look in safety glasses, they are more likely to put their eyewear on – and keep it on.
Dark brown, gray or mirrored lenses may be the preferred street fashion, but such tints are not always a safe choice at work. Many lens tints perform specific roles in protecting the eyes from industrial hazards. Hues such as orange, cobalt and scarlet serve a role in blocking targeted spectrums of light and enhancing a worker’s visual acuity. Likewise, what may be an ideal tint for one application may be hazardous when used in another.
Visible & invisible hazards
Safety eyewear is designed to protect the wearer from impact, chemicals and airborne particles, and must meet the American National Standards Institute’s (ANSI) Z87.1-2010 standard for occupational eye protection. But in many applications, the eyewear’s lenses also serve to protect the wearer from other visible and invisible hazards. From blinding laser light to invisible ultraviolet and infrared rays, specialized lens tints can provide the added protection workers require to stay safe and conduct their jobs effectively.
Employers are responsible for providing the proper type of safety eyewear and shade of lens tint based on the hazards present. Making an informed choice is vital to worker safety and directly supports productivity. But with such a wide variety of available tints, the selection process can seem overwhelming. This article looks at specialized lens tints and their intended uses, to support safety managers in selecting the best option for the unique lighting applications their workforces face.
Tints for going from light to dark
In many industries workers are on the move, transitioning from one location to another – and the lighting in each locale can differ significantly. In warehousing, for instance, a worker may unload goods from a truck parked outdoors and drive them into the warehouse. When transitioning between bright outdoor and dimly-lit indoor environments, the eyes can take up to several minutes to adjust, leaving workers’ vision temporarily compromised and their safety at risk. Plus, wearing dark lenses indoors – or clear lenses in bright sunlight – can affect workers’ ability to see hazards clearly. A common solution is to outfit workers with two pairs of safety eyewear – one for each environment. But this not only doubles a worker’s personal protective equipment, but it also requires them to remove and replace eyewear frequently, leaving them unprotected in the work zone.
For workers who experience frequent lighting transitions, look for photochromic safety lenses. Designed specifically for variable light applications, these advanced lenses respond to ultraviolet light through a chemical reaction, and automatically transition from clear or light gray during indoor use to a deeply tinted shade when outdoors. ANSI-approved lenses intended for variable light applications are marked with a “V” under the revised ANSI 2010 standard. For less extreme lighting transitions, a light mirror-coated lens may also be considered, which allows for good light transmission while protecting against glare outdoors.
Lenses that block sunlight and glare
In outdoor environments, it is vital that workers’ eyes be protected from the sun’s visible and invisible rays. Optical radiation is an easily overlooked hazard, yet its effects range from short-term injuries to permanent vision loss. In fact, long-term exposure to the sun’s invisible ultraviolet light is a leading cause of cataracts and blindness. Employees who spend any time outside should be outfitted with eyewear that blocks more than 99 percent of UV rays. Look for safety lenses marked with a “U,” which denotes ample protection from both UVA and UVB spectrums.
Outdoors, workers are also exposed to direct sunlight and glare, forms of visible optical radiation also commonly overlooked in safety audits. Overexposure to direct and reflected light causes headaches as well as eye fatigue, redness, dryness and irritation, all of which can undermine productivity. To combat natural light hazards, eyewear with standard gray, brown or mirrored lens tints offer suitable protection and may be selected based on user preference. In environments where glare from sunlight is reflected off surfaces such as water, sand, glass, sheet metal or concrete, look for lenses that are mirrored, polarized or darkly tinted and are marked with an “L” for effective glare reduction.
Colored lens tints for specialized applications
To support visual function in applications with specialized lighting, unique dyes are incorporated into the polycarbonate lens material that absorbs select wavelengths of radiant energy (light). Such lenses can manipulate light to reduce a spectral hazard or to provide distinctive filtration for specific viewing tasks.
For instance, in operations where a high level of yellow light is present, specialized blue lenses counteract the resulting color distortion and help prevent eye fatigue.
Vermilion (scarlet) lenses are useful in some inspection operations where the color shift enhances contrast or highlights shadowing for better inspection results and increased productivity.
While orange lenses effectively filter blue and violet light present with UV curing lamps, amber lenses are commonly used to aggregate reflected light for a brighter view in low-light environments.
Deep cobalt lenses are valued by furnace workers for their ability to deliver excellent spectral performance while protecting from harmful infrared rays.
Remember, many colored lenses affect the wearer’s ability to identify colors correctly; selecting lenses with true color recognition is essential for traffic signal identification and other applications that rely on color coding.
While impact protection remains safety eyewear’s leading function, other factors including style and specialized visual performance contribute to an overall solution that addresses workplace hazards as well as productivity and compliance issues faced by the safety manager. Advances in lens technology enable workers to benefit from UV filtration, infrared absorption and enhanced visual perception across myriad unique industrial applications. By understanding each lens tint’s unique purpose, employers can choose safety eyewear that supports a healthier, more productive and compliant workforce.