Because of the popularity of sunglasses as a fashion statement, it’s often forgotten or overlooked that sunglasses play an important role in maintaining good eye health. Sunglasses (also called shades or sunnies) are a form of protective eyewear with a specific purpose of preventing the sun’s ultra-violet light rays from damaging our eyes. Ultra-violet light (UV) is defined as, “that portion of the electromagnetic spectrum extending from the violet or short-wavelength end of the visible light range to the x-ray region.” A more lay definition is, “the invisible lights rays that are a part of the energy that comes from the sun which can burn the skin or cause eye damage.”
UV radiation is made up of three types of light rays – ultra-violet A (UVA), ultra-violet B (UVB), and ultra-violet C (UVC). UVC poses no threat to life on earth as it can’t penetrate the earth’s protective ozone layer. However, UVA and UVB light rays can and do penetrate the ozone layer and therefore reach the surface of the earth. It is for this reason that the American Optometric Association, the nation’s foremost body representing tens of thousands of eye-care specialists, recommends anyone exposed to sunlight to wear sunglasses to block or shield their eyes from ultra-violet light. UV radiation can cause short-term and long-term ocular problems such as cataracts, ptergium, and various forms of eye cancer.
What To Look For
When purchasing sunglasses, look for sunglasses that reflect or filter out 99% or more of the UV light. Sunglasses that meet this requirement are labeled UV400.
Most brand-name sunglasses such as EyeDope, will carry the European CE mark on the inside temple arm (as shown on the picture below) which designates that the sunglass offers the wearer a safe level of protection from UV light.
Mystical by EyeDope - UV400 Protection
Broad Selection of Styles
To meet the varied tastes of sunglass enthusiasts around the world and to recognize the fact that there are several types of facial shapes and sizes, sunglasses are manufactured in a very large range of styles and sizes. One thing you should keep in mind when purchasing sunglasses and being cognizant of your eye health is that broad temple-arm frames offer added protection to the wearer as they block out stray UV light coming in from the side. Take another look at the picture above. Notice how wide the side arm is.
Polarized sunglasses are specialized eyewear designed to reduce the glare from surfaces such as water, snow, and glass. Glare distorts the true color of objects and makes them harder to distinguish. Polarized sunglasses may have a slightly higher cost due to the specialized lenses, but the wearer will experience a world of heightened clarity and vivid color across the spectrum.
Not all sunglasses lenses can be polarized. Current polarization technology can not be applied to gradient lenses. Neither can it be applied to mirrored sunglasses. However, mirrored sunglasses do reduce glare by reflecting much of the light that hits the lens surface.