Protective eyewear that incorporates a "general purpose" lens tint will effectively provide glare and UV protection while enhancing visual comfort for these workers. If these workers take photosensitizing drugs, had cataract surgery, or experience any type of retinal disorder, their eyes may be more susceptible to this type of harmful light. Outdoor workers, such as gardeners and groundskeepers, masons, highway construction workers, lifeguards, pilots, and roofers to name a few, are exposed daily to solar UV radiation and intense visible sunlight. Many work applications include daily exposure to ultraviolet light and visible glare. As with all personal protective equipment, it is the employer's responsibility to conduct an on-site or workplace hazard assessment. This lens tint is a recommended alternative to traditional gray lenses. The Uvex espresso "blue blocker" lens will absorb 97% of blue light, thereby enhancing contrast. Blue light makes things appear hazy and out of focus. While blue light is not harmful to the eyes, it can cause eye fatigue. The Uvex espresso lens is also a "blue blocker" lens. It is suggested as a general purpose sunglass lens for driving and most outdoor activities. The espresso lens tint also provides true color recognition and meets the traffic signal color requirements of ANSI Z80.3-1996. The espresso lens will absorb 99.9% of UVA and UVB radiation up to 400nm. This means 15% of the available light will pass through the lens. This sunglass tint is brown/amber in color and has a Visible Light Transmittance of about 15%. Uvex manufactures an espresso lens tint for outdoor work environments where sunlight and glare cause eyestrain and fatigue. If these workers take photosensitizing drugs, or had cataract surgery, or experience any type of retinal disorder, their eyes may be even more susceptible to this type of harmful light. Outdoor workers, such as gardeners and groundskeepers, masons, construction workers, lifeguards, pilots, and roofers to name a few, are exposed daily to solar UV radiation and intense visible sunlight. While impact protection is certainly a vital requirement for any safety eyewear, it is no longer the sole function. Under these circumstances, Uvex discourages night time use of amber lenses as general-purpose eyewear.įor general purpose use, Uvex suggests clear lenses indoors and sunglass tints, preferably gray or brown, for outdoors. Amber lenses that are deeper in color would result in an even greater loss of transmittance.
The calculated transmittance of a Uvex amber lens drops to 70%, which is a 20% loss of VLT. Since amber lenses filter out blue light, the direct effect is to reduce the light available.
Night time or "scotopic" transmittance is calculated using a weighting factor in which the bell curve is shifted toward the blue portion of the spectrum. In most cases, amber lenses would be acceptable for daytime use.Īt night, however, the eye processes information differently. In addition, the lenses satisfy the color limit requirements of ANSI Z80.3, the sunglass standard, as they relate to properties that influence traffic signal recognition.
It weighs the eye's ability to see in a bell curve centered around the green portion of the spectrum. Uvex amber lenses transmit about 90% of the available light when "photopic" or daytime transmittance is calculated according to the requirements of ANSI Z87. In these cases, amber lenses will cut down or eliminate the haze associated with the blue light, giving the perception of clearer and brighter vision. This is particularly noticeable when light conditions are hazy such as at dusk or on foggy days. Green light is most efficiently processed by the eye, while blue light is not as easily focused, and can reduce contrast. In the case of amber lenses, the yellow color filters out light at the blue end of the spectrum while allowing green and red light to pass. Lenses are available in a variety of tints to reduce glare, screen hazardous radiation, or to provide other task specific filtration.