Displaying all posts for ‘cr 39’

Selecting Sunglasses for Pilots

by iflyasa November 5, 2009 » Add the first comment.

While adding to the mystique of an aviator, sunglasses protect a pilot’s eyes from glare associated with bright sunlight and the harmful effects from exposure to solar radiation. Lenses for sunglasses that incorporate 100% ultraviolet protection are available in glass, plastic, and polycarbonate materials. Glass and CR-39® plastic lenses have superior optical qualities, while polycarbonate lenses are lighter and more impact-resistant. The choice of tints for use in the aviation environment should be limited to those that optimize visual performance while minimizing color distortion, such as a neutral gray tint with 15 to 30% light transmittance. Polarized sunglasses are not recommended because of their possible interaction with displays or other materials in the cockpit environment.

Aviators’ Sunglasses Lens Material Options

by av8er » Add the first comment.

In one of my previous post – Sunglasses for Pilots, we talked about why it is extremely important for a Pilot to be very careful about choosing proper quality and material for the Sunglasses. 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, making 100% ultraviolet protection a wise choice when selecting eyewear.