A pilot's most important asset is his visual acuity, thus wearing sunglasses as an effective protection tool is clearly essential because pilots' sunglasses significantly reduce harmful effects of the sunlight and prevent eye fatigue and tissue damage.
Interestingly, sunglasses used by pilots protect their eyes against UVA-UVB rays 99% to 100%. Fortunately, the extremely harmful UVC ray for the eyes is absorbed by the ozone layer before reaching the earth's surface.
This protection is mainly provided by the lenses used in pilots' sunglasses. Irrespective of which group of pilots (commercial, military, exploratory, or recreational) use these sunglasses, the lenses used in them have a significant role in improving their efficiency and tangibly enhance the quality of images received by the visual system.
Like ordinary sunglasses, this type also uses convex glass, single layer plastic and polycarbonate lenses. The difference lies in their resistance against severe impacts, breaking and scratches and their perfect absorption of ultraviolet radiation.
Performance and Color Variations of Pilots' Sunglasses
Pilots' glasses come in a variety of colors and aviators have numerous options. However, gray, greenish gray, and brown are the most popular colors, which will be further introduced below:
- Gray: The least change in natural color
- Greenish gray and brown: greater moderation and reduced dispersion of blue and violet lights
The vision is limited by the color of some lenses, and therefore according to the international aviation guidelines, pilots should avoid using them. These colors mainly include yellow and orange, which are not recommended due to interference in detecting navigation lights, improper reading of maps, notifications, and instruments.
According to aviation medical standards, pilot sunglasses should be able to prevent 70% to 85% of entry of visible lights, without causing noticeable color change.
On the other hand, using polarized lenses also has limitations, since they allow minimum entry of visible lights, and besides, they cause interference in observation of cabin displays.
Irrespective of their visual attractiveness, pilots' sunglasses protect aviators' eyes against harmful sun radiations, and thus they are among the most important flight safety tools. Therefore, they have been meticulously made and selected for decades.