Sunglasses help defend a pilot’s most important sensory asset: vision. A quality pair of sunglasses is a basic necessity in the cockpit to enhance performance. In addition to reducing the impacts of unforgiving sunlight, sunglasses also decrease eye fatigue and provide protection for the ocular tissues from exposure to harmful solar radiation. Additionally, they protect the pilot’s eyes from impact with objects, such as flying debris. Sunglasses can also aid the dark adaptation process, which is delayed by prolonged exposure to bright sunlight.
One primary reason it’s recommended to wear sunglasses is that it can prevent potential damage to the eyes, including radiation exposure. It’s important to know that UV radiation increases by roughly 5 percent for every 1,000 feet of altitude.
The History of Aviator Sunglasses – The One That Started it All
In the 1920s, the U.S. Army Air Corps put out a manufacturing call for anti-glare goggles suitable for high-altitude flying. The optical instruments company, then known as Bausch & Lomb, delivered the Anti-Glare Aviator Sunglasses. These sunglasses featured metal frames with large teardrop-shaped lenses to shield peripheral vision with a green tint. At the time, they were considered the best way to protect the eyes without affecting color perception. Today, these sunglasses are recognized as the aviator-style, which has become a standard issue for pilots.
In the 1930s, aviators were first introduced into the military, representing a brand that embodied strong, bold and brave characteristics. Later made a standard issue, the frames took on the identity of the heroes associated with them.
Previously named “Anti-Glare Sunglasses”, Bausch & Lomb rebranded the anti-glares as Ray-Ban sunglasses, because they banish rays, in 1937 and started selling them to the general public. Although Ray-Bans weren’t the first mass-produced sunglasses, they were the first sunglasses brand in history.
What type of sunglasses to avoid when flying
Nearly all pilots wear sunglasses of some kind when they’re flying by day. The Federal Aviation Administration recommends particular lenses on sunglasses over others. A gray tint, for example, is a good choice because it distorts color less than yellow, amber, or orange. It’s important to note that the colored lenses can make it difficult to distinguish navigation lights and signals.
In addition to the tint of sunglasses, most people may not be aware that polarized lenses are a bad choice for pilots. Crazy right? There is no doubt that polarized lenses are remarkably effective at eliminating glare, making them an ideal choice for outdoor activities such as; skiers, golfers, boaters, and other sportsmen. However, there is one activity where polarized lenses are actually detrimental: flying. Polarized lenses can reduce the ability to read instruments that already incorporate anti-glare filters. In addition to that, they interfere with the ability to read LCD instruments, which emit polarized light.
On the plus side, the government doesn’t play favorites when it comes to the shape of a pilot’s frames, so you will have a little more freedom when it comes to choosing the best sunglasses that embody your personal style. With that said, there are some general guidelines to selecting the right pair. For example, frames with small lenses are less than ideal. Along with small lenses, it’s important to avoid any designs that might interfere with communication headsets. This still leaves pilots with a fair amount of leeway when it comes to choosing their sunnies. In the end, most pilots do, in fact, end up sporting Ray-Ban aviators.
So what are the best sunglasses for life above the clouds?
The American Optometric Association recommends wearing sunglasses that incorporate 99 – 100% UVA and UVB protection. Fortunately, UVC, the most harmful form of UV radiation, is absorbed by the atmosphere’s ozone layer before it actually reaches the Earth’s surface. However, some scientists believe that depletion of the ozone layer may allow more UV to pass through the atmosphere, making 100% UV protection a wise choice when selecting eyewear.
The three most common lens materials today are optical-quality “crown” glass, monomer plastic (CR-39®), and polycarbonate plastic.
Lenses made from crown glass provide excellent optical properties. Crown glass is more scratch-resistant, but heavier and less impact-resistant than plastic. Although crown glass absorbs some UV light, absorption is improved by adding certain chemicals during the manufacturing process or by applying a special coating. Crown glass lenses retain tints best over time, but for higher refractive correction, the color may be less uniform, as part of the lens will be thicker than others.
CR-39® Plastic Lenses
CR-39® plastic lenses possess excellent optical qualities, are lighter in weight, and more impact-resistant. CR-39® lenses tint easily and uniformly, even for those requiring a great deal of refractive correction, but do not hold tints as well as glass. As far as longevity goes, CR-39® plastic lenses can be bleached and retinted if fading becomes excessive at some point.
Polycarbonate Plastic Lenses
Polycarbonate plastic lenses are lighter than CR-39® and the most impact-resistant lenses available. Polycarbonates plastic lenses have a low Abbe value, indicating their inherent optical aberrations. The application of an anti-reflective (AR) coat can improve optical quality, particularly when a high refractive correction is required. The anti-reflective treated lenses have built-in UV protection and are manufactured with a scratch-resistant coating that is much stronger than that applied to CR-39® lenses.
In conclusion, there is no question that when a pilot is flying at higher altitudes, his or her eyes are at risk of being exposed to higher levels of ultraviolet (UV) radiation. This exposure puts the pilot at risk for some serious eye problems in the future. In addition to the potential long-term problems, the glare from the sun can make it difficult for a pilot to maintain a positive situational awareness of his or her surroundings. So whether you decide to invest in a high-quality pair of sunnies or stick to finding ones that are a lower cost, it’s always recommended that you are proactive when it comes to protecting your most important sensory asset.