For most of the past week (10-10-10 through 10-16-10) people around the world were glued to their televisions watching the incredible rescue of 33 miners who had spent 69 days 2,600 feet underground.
As they were brought to the surface, one by one, each were fitted with a pair of Oakley sunglasses to protect their eyes from the blinding lights illuminating the area around the rescue tunnel.
Oakley donated 35 pair of Oakley Radar sunglasses to be used to protect the miners eyes as they reached the surface and their eyes began to adjust to light once again. These are polarized sunglasses and you can see what they look like in the photo on the right.
How Do 33 Pairs Of Sunglasses Relate To Pilots?
Sunglasses are a very important item for pilots to wear when you consider the fact that, for the most part and regardless of time of year, they are flying their aircraft out in the clear blue sky and closer to the sun by thousands of feet. Today, modern aircraft have glass cockpits where instrumentation displaying flight and engine instruments are displayed on liquid crystal panels, or LCDs.
Light From LCD Panels Is Horizontally Polarized
In order for a liquid crystal display to work there are 4 things necessary:
- Light can be polarized;
- Liquid crystals can transmit and change polarized light;
- The structure of liquid crystals can be changed by an electric current;
- And transparent substances can conduct electric current.
The important thing here is that the light emanating from an LCD display is horizontally polarized. At the same time, polarized sunglasses are manufactured to eliminate
horizontally polarized light.
If you are wearing polarized sunglasses while driving a car with a heads up display, or flying an airplane with a glass cockpit, much of the information you need can not be seen. In order to see the displayed information in bright sunlight and without distortion, or missing it altogether, pilots and drivers of cars with these displays need non-polarized sunglasses!
In these modern times our world is filled with all kinds of devices with LCDs, from our hand-held mobile devices to computers to our television sets. As the screens get larger and the units thinner LCD technology and Plasma technologies become more prevalent. LCDs are lighter than Plasma screens, and Plasma screens can not be manufactured in the smaller sizes like the LCDs you will find in glass cockpits.
But There Are Even More Serious Problems
It has been well documented that ultraviolet rays (uv rays) are harmful to skin, but they are also harmful to our eyes. Various eye problems have been associated with overexposure to uv rays; for example, UVB rays are thought to cause pingueculae and pterygia which are growths on the eyes surface which can cause distorted vision. They can also cause photokeratitis, which is a painful inflammation of the cornea known commonly as "snow blindness." The effect is normally temporary, lasting 1 to 2 days.
UVC Rays, Or "Blue Light"
These are the highest energy uv rays and potentially the most harmful to skin and eyes. While the ozone layer blocks most of them, prolonged or frequent exposure can lead to serious problems for the eyes. Blue rays have one of the shortest wavelengths in the visible spectrum (red is the longest). As a result, the color blue will focus slightly in front of the retina which is the “focusing screen” in our eye.
Sunglasses which block out 98 to 100% of uv rays are essential for pilots because for every 1,000 feet in altitude we fly, the strength of uv rays increases by 4%. In addition, sunglasses with special filtration to block out the blue rays and only allowing the rays through that indeed focus clearly on the retina not only protects the eyes but allows objects to appear sharper and clearer. Our pupils close in bright light to limit the amount of light entering the eye, and open wider at night light the lens of a camera. So when you put on conventional sunglasses the amount of light that enters the eyes is reduced, but the pupils open wider allowing more of the harmful blue and ultraviolet light to enter the eye.
Fortunately, there is a very good solution. A company called Randolph Engineering has been manufacturing specialized sunglasses for the military since 1972 which block 98 to 100% of ultraviolet light, and which effectively block out the blue light.
With the gray or green (AGX) lenses your eyes are completely protected, and you are able to see objects like LCD panels and other aircraft clearer and sharper, making you a safer pilot.
To order you can simply choose which pair(s) you want and click the "Add to Cart" button, or if you prefer simply call 1 (866) 440-2461 and ask for either John or Betty who will handle your order promptly and courteously.
Until next time keep your wings straight and level Hersch! JetAviator7
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