Sunglasses for Pilots

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Sunglasses for Pilots Empty Sunglasses for Pilots

Post  Admin on Tue Dec 22, 2009 10:49 pm

Sunglasses help safeguard a pilot’s most important sensory asset — vision. A quality pair of sunglasses is essential in the cockpit environment to optimize visual

performance. Sunglasses reduce the effects of harsh sunlight, decrease eye fatigue, and protect ocular tissues from exposure to harmful solar radiation.

Additionally, they protect the pilot’s eyes from impact with objects (i.e., flying debris from a bird strike, sudden decompression, or aerobatic maneuvers). Sunglasses can also aid the dark adaptation process, which is delayed by prolonged exposure to bright sunlight.

RADIATION. Radiation from the sun can damage skin and eyes when exposure is excessive or too intense. Fortunately, the Earth’s atmosphere shelters us from the more hazardous solar radiation (i.e., gamma and X-ray); however, both infrared and ultraviolet radiation are present in our environment in varying amounts. This is dependant upon factors such as the time of day and year, latitude, altitude, weather conditions, and the reflectivity of surrounding surfaces. For example, exposure to ultraviolet radiation increases by approximately 5 percent for every 1,000 feet of altitude.

Atmospheric infrared energy consists of long-wavelength radiation (780 to 1400 nanometers nm, see Figure 1). The warmth felt from the sun is provided by infrared radiation and is thought to be harmless to the skin and eyes at normal atmospheric exposure levels. More hazardous to human tissues is short-wavelength
ultraviolet radiation. Ultraviolet is divided into three bandwidths: UVA (400 – 315 nm), UVB (315 – 280 nm), and UVC (< 280 nm).1 Excessive or chronic exposure to UVA and, to a greater extent, UVB, can cause sunburn, skin cancers, and is implicated in the formation of cataracts, macular degeneration, and other eye maladies.

The American Optometric Association recommends wearing sunglasses that incorporate 99 – 100% UVA and UVB protection. Fortunately, UVC, the most harmful form of ultraviolet radiation, is absorbed by the atmosphere’s ozone layer before it reaches the Earth’s surface. Some scientists believe, however, that depletion of the ozone layer may allow more ultraviolet to pass through the atmosphere,2 making 100% ultraviolet protection a wise choice when selecting eyewear.

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