Greetings and welcome aboard the CF, UDIU.
sunglasses, one of the most important things to look for is 99% to 100% ultraviolet (UV) protection (both UV-A and UV-B)
. Darker sunglasses decrease the amount of visible light that passes through the lenses, compared with lighter lens tints, but they don't necessarily provide greater protection from invisible UV rays. For adequate sun protection, make sure your sunglasses block 100 percent UV
, regardless of the color or darkness of the lenses. Boaters should consider wearing wraparound UV glasses to cut down the amount of UV radiation that may enter the eyes from the periphery.
Polarized lenses, using horizontally aligned polarizing micro crystals, block all vertical light and protect your eyes from reflective glare, but they do not offer additional UV protection. Polarized sunglasses cut reflections from the surface of the water
far better than ordinary sunglasses, and this allows you to see what's under the water
. While most polarized lenses are also UV-blocking glasses, polarization by itself does not protect your eyes from UV radiation.
Sunglasses that have anti-reflecting (AR) coating, applied to the back side of the lenses, reduce glare by preventing light from reflecting off the back surface of your sunglasses.
For comfort and safety
, choose sunglass lenses that are both impact resistant and scratch resistant. Polycarbonate lenses are often the best choice for sunglasses, because they are lightweight, and significantly more impact resistant than lenses made of glass or other materials. According to the American Academy of Ophthalmology (AAO), polycarbonate lenses block ultraviolet radiation without any coating, but plastic lenses must have the coating added to be considered UV blocking glasses.