When considering the purchase of a pair of aviator sunglasses, most people don’t give a thought about the lenses and just consider how “cool” they look when they put them on. While looks may seem to be important, the ability of the lenses to provide adequate protection for your eyes is far more important.
A quality pair of aviator sunglasses starts with the selection of the lenses. The lens material must have a uniform composition and be perfectly transparent. In addition, the lenses must be ground and treated in such a way as to provide maximum protection from harmful uv radiation.
What Are The Choices In Lens Material?
Generally speaking there are three choices in lens material:
At first the only choice for lenses was glass, but as technology improved plastic and then polycarbonate became available for making sunglass lenses. With several choices on the market available it may be confusing as to which would be best for you.
Plastic lenses have become popular mainly because they are light in weight and therefore more comfortable to wear. They eliminate the problem of glass lenses which sometimes slip down your nose and having to constantly push them back up.
One of the problems with plastic lenses, however, is that they can easily be scratched. To solve this problem plastic lenses have a scratch resistant coating applied to the lens and, if kept clean, will remain scratch free for a long time.
The advantage of polycarbonate lenses is that they are thinner, lighter and shatterproof. Because these lenses are impact resistant you could drop a steel ball on the lens from quite a distance and the lens would not break or shatter.
Glasses with polycarbonate lenses are known as safety glasses because they do a great job in protecting your eyes from injury. They are impact resistant because the lenses are made of a very soft, pliable material; however, they will scratch very easily without proper care.
Glass lenses are heavier than either plastic or polycarbonate lenses and are scratch resistant eliminating the need for a scratch resistant coating. However, drop a pair of glasses with glass lenses and they very likely will shatter.
On the other hand, glass lenses provide the very best visual acuity. Visual acuity is the acuteness or clearness of vision, which means everything you see through glass lenses will be sharper than with any other lens material.
Liquid Crystal Displays (LCDs)
Today we are surrounded with devices like smart phones, car dashboard displays and computer screens which use liquid crystal displays to present information to us.
Because LCDs use a polarizing filter with a vertical axis the information displayed on these screens can be difficult or impossible to see with polarized lenses. Polarized lens are specially designed to eliminate vertically polarized light waves, which means trying to view an LCD screen with polarized glasses or sunglasses is a problem.
The solution, of course, is to wear aviator sunglasses that are not polarized. In fact, the only real advantage for wearing polarized sunglasses is when you are on the water which then allows you to see some depth into the water.
The Best Choice For Pilots
A pilot’s eyes are their most important asset, and pilots need to be able to see everything as clearly as possible, including the LCD displays which provide flight and navigation information to them from the aircraft’s panel.
This means that aviator sunglasses with non-polarized glass lenses are the very best choice for pilots. In fact, these would also be the best choice for anyone who drives an automobile with an LCD instrument panel as well.