Five things to look for in sunglasses
By John L Henahan, OD, FAAO
Special to The Citizen
Spring has finally sprung, and the pollen is diminishing to the point that you actually want to go outside, so it is time to consider how you will protect your eyes this summer. Here are the top things to look for when purchasing sunglasses.
UV Protection. Sunglasses are like sunscreen for your eyes. Just as invisible UV light can cause sunburn, it can damage your eyes. Protecting your eyes from UV light is critical in reducing the likelihood that you will develop cataracts and macular degeneration, which are the leading causes of vision loss in Americans over age 65. They can also protect against unattractive and sight threatening growths on the white part of the eye called a pterygium (“ter-ridge-e-um”). It takes decades for UV light to cause this type of damage, so it is essential to protect your eyes starting in childhood. Most sunglasses in the US will be listed with a “UV400” designation that indicates it has UV protection. More expensive sunglasses do not necessarily mean more UV protection, but rather relate to better optical clarity and higher quality frames.
Polarized lenses. There are two main types of lenses, polarized and tinted. While both provide protection from UV light, tinted lenses merely reduce the brightness by darkening the lens. This is far better than no protection at all, but it doesn’t come close to the protection and glare reduction that you gain from polarized sunglasses. Polarized lenses are tinted and they block 100% of the light rays from certain types of reflections including those on the water and when the sun glare that accompanies bright days.
Optical Quality. Although most lenses protect your eyes from UV light, the optical quality of a lens determines how sharp and distortion free your vision will be. Generally speaking, fashion sunglasses (even expensive brands like Coach and D&G) will have lower optical quality than sports sunglasses, such as Costa del Mar, RayBan, Oakley and Maui Jim. Costa del Mar is unique in offering the only second-generation polarized lenses. These unique lenses block UV light and block yellow light. This allows for improved clarity of vision especially when looking into the water. The 580 lenses are prized by fisherman as well as others who spend a lot of time on the water.
Lens Material. Glass lenses provide the highest quality of vision, followed by plastic. Although glass lenses are reasonably strong, they should not be purchased if protection from impact is a key consideration. Polycarbonate is the strongest material and is a great choice for people such as military/law enforcement, construction workers, landscape company employees, etc.
Lens Color. Lenses most commonly come in gray, but are also seen in shades of brown as well as green. In fact, the venerable RayBan Aviator worn by WWII pilots used a green (G-15) lens. Generally brown lenses are best in overcast conditions, gray lenses excel on sunny days and the G-15 lenses balance the performance of brown and gray lenses.
Whatever you choose for sunglasses, keep in mind that no sunglasses at all is the worst choice. Polarized gray or brown sunglasses are the best choice for almost everyone, and tinted sunglasses are a great choice for pilots who cannot use polarized lenses in the cockpit.
Dr. John Henahan is a Peachtree City resident and founder of Spectrum Eyecare. Visit his website at speceye.com for more information