Q: I have heard that inferior sunglasses can be more damaging to your eyes than wearing no sunglasses at all.
Apparently, when one wears sunglasses the pupil widens; if the sunglasses have
poor UV protection, then the eyes are
damaged more by the sun's rays. Is this correct, or are any sunglasses better than none? — G.H., Malaysia
A: I have heard this as well, but I have never seen any confirming
studies. It does sort of make sense, though. But remember, even clear lenses can
have 100 percent UV protection.
Having said that, I do highly recommend quality lenses for best comfort and vision — both in regular glasses and sunglasses. Why take chances with your eyes? — Dr. Dubow
Q: You may not wish to promote certain sunglass brands.
But I am confused about how to find a cheaper pair that still can guarantee the
99 percent to 100 percent UV protection. Many are made in
China and say 100 percent UV protection. But how do I really know? An answer to this could
help many people who cannot afford higher prices. — M.D., North Carolina
A: Typically, most sunwear lenses will be
UV absorptive to some degree. If lenses are marked CR-39R plastic, about 88
percent of
UV light is absorbed.
If sunglasses are polycarbonate, UV absorption will
be 100 percent.
All better quality polarized non-prescription
sunglasses sold through optical stores
are 100 percent UV absorbing. For the very inexpensive polarized sunglass — thin, bent
sheet polarized types provide UV absorption. Lenses that are polycarbonate are usually UV
absorptive. However, many cheap sunglasses use a material called triacetate. This material
absorbs only about 40 percent of the UV rays. Lenses may also be made of other acrylic
materials, which will vary from partially to fully absorbent.
To know that your lenses are 100 percent UV absorbing, purchase them from reputable companies,
specialty sunglass stores or from an optical professional. — Mark Mattison-Shupnick, master
optician
Q: What is the best color for prescription sunglass lenses? I was given red, and I do not think they are very protective. Plus, they change the color of things, and there are red spots in them. — J.N., Pennsylvania
A: Sunglass lens colors are really a personal preference. As you noticed, some change your perceptions of color, brightness and contrast, and some don't.
The most important feature to look for in a sunglass lens is how much UV radiation it absorbs — you want 100
percent for maximum protection. It is also important to get lenses that are ground rather than punched, to minimize distortion.
A color we call neutral density gray will darken the world but not change your color perceptions. The tint I prefer in my sunglasses is called G-15, which is a combination of gray and green. It is the original tint that Bausch & Lomb used in their Ray-Ban sunglasses for pilots. — Dr. Dubow
[Read more about sunglass lens colors or sun lens colors for winter sports eyewear.]
Q: Are there any doctor recommendations for polarized sun lenses? — L.K., Ohio
A: Polarized lenses are great for those who spend time on water, drive a lot, etc. The polarization actually cuts out the light coming from the horizontal meridian
while allowing in the light coming in from the vertical meridian. In other words, it blocks the light that reflects in from water or the highway, reducing glare.
Most professional optical dispensaries have a demonstration display of how polarization works — check it out. — Dr. Dubow
[Read more about polarized lenses.]
Q: Can't sunglasses be dangerous for the eyes because they dilate the pupil and cause extra UV exposure onto the lens? — R.G., Illinois
A: Well, yes. But NOT good quality ones. Properly manufactured sunglasses absorb 100
percent of the
ultraviolet (UV) rays that can damage your eyes. If you have doubts about your sunglasses,
many eyecare practitioners and optical shops have little machines that can measure the amount of UV a lens can absorb.
It takes just a few seconds to read the UV meter to ensure you are properly protected. — Dr. Dubow
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