Q&A on Eyeglass Frames
Q: I saw a pair of eyeglass frames that are size 48-19-140. What does this mean, and how can I determine what my size would be? E.H., New York
A: All frames have standardized size measurements to help manufacturers and optical personnel fit them appropriately for consumers. The first number, 48, represents the size of the lenses. The second number, 19, is the bridge size, which ensures that the frame fits your nose. The third number, 140, is the temple length temples are the parts that hook over the ears.
Each person is shaped differently, of course, and would require different frame measurements. And to make it more complicated, frames vary by their shapes and sizes, so there is no set of numbers that would apply to one person for all frames. Each frame must be fitted individually.
If you want an excellent frame fit, go to an optical boutique and get some help from the trained personnel it will be well worth your time! Dr. Dubow
Q: I'm real nearsighted (I can't see far away). How come I can always see better when I get a plastic type of frame instead of a metal type with nose pads? P.T., Pennsylvania
A: Very observant! I have noticed this strange phenomenon with some of my patients as well.
Although I really don't know the answer, I am guessing that the plastic rims around the lenses make for a better depth of focus. I have tried having patients curl their hand around a rimless or metal frame, sort of like looking through your fingers like you would binoculars, and this also seems to help improve sharpness of vision. It could also be that the frame (or the fingers) help reduce lens aberrations and light scatter, thereby improving clarity.
Here's a follow-up comment from another optometrist:
Dr. Dubow, here's an answer to the phenomenon of high myopes seeing better with plastic frames rather than metal ones with nose pads: lens effectivity!
Very often, nose pads are adjusted (or, more often, not adjusted) to give the patient a greater vertex distance the distance between the back surface of the eyeglass lenses and the front of the eyes than they otherwise would have with a properly fit plastic frame.
It's easy to spot a poor-fitting bridge with most plastic frames, but not so easy with nose pad frames.
Of course, this also explains why this phenomenon is more likely to be noticed by our more highly myopic patients, and why a frame adjustment to decrease the vertex distance usually corrects the problem (in the experience of my patients and myself, as well). Steven V. Vachula II, O.D., Massachusetts
Good point, Dr. Vachula. I appreciate your adding information to my already astute and insightful answer!
Seriously, I was assuming the eyeglasses were optimally adjusted for vertex distance, pantoscopic tilt and optical center alignment. And you know what they say about "assuming!" Thanks for helping me out. Dr. Dubow
Q: I have developed what I believe is a sensitivity to silicone my skin reacts to nose pads on my glasses, the skin becomes red and eventually (if not treated) will develop a blister-like sore.
I have tried the "hard" nose pads, but they also irritate, though not as severely as the soft pads. Is there a source for non-silicone nose pads? C.S., Canada
A: Great question! I asked Pat, one of our terrifically talented opticians.
She said that vinyl nose pads are indeed available for people who are sensitive to silicone. She added that it is very likely your frame also needs to be readjusted to distribute its weight evenly, taking the pressure off your nose.
She also pointed out that vinyl nose pads come in different sizes and shapes yours may need to be altered to fit you better.
My thought is... try contact lenses. Your nose will appreciate you! Dr. Dubow
[More info from optician Liz DeFranco: Optical supplier Hilco distributes "soft" nose pads that are not silicone. This type of pad is commonly found on kids' glasses that feature a comfort bridge (an adjustable one-piece nose pade) to fit small faces. The material also is available for adult-size adjustable comfort bridges and traditional-style nose pads as well. All trained opticians should be familiar with non-silicone nose pad options.]
Q: I have an allergy to nickel. Can wearing metal frames that are not stainless steel or titanium be a cause of my eyes feeling gritty and like sometimes there are rocks in them? They also tear more and feel stressed.
I was also wondering about the anti-reflective coating if someone with an allergy to nickel would have a problem. If the metal part touches my skin, I get a reaction. But can my eyes themselves react? D.D., Nevada
A: My motto is, "Never say never." I would imagine an allergy could cause your symptoms, but it would be rather unusual to say the least.
It sounds to me as though you might have dry eyes especially living where you do. I do not think an anti-reflective lens coating would bother you at all. I'd recommend you get tested for dry eyes, though. Dr. Dubow
Q: My child is only 3 years old, and his glasses frames are so small that I can't seem to find any kind of clip-on or other shade that would fit over them. I bought him a pair of Flexon eyeglasses costing about $300. The only shades they have are custom-made and cost about $150. I am trying to avoid this expense.
I thought of using a window decal type UVB-UVA protective film that could be cut to match his frames, and that could be taken on and off. But I don't know if this exists. I would take any help you can offer! J.D.
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A: If you don't want to have a sun clip specially made to fit your child's small frames, you might consider Transitions (photochromic) lenses. These lenses darken automatically in sunlight. I think Transitions lenses are a great option for kids, because they are always there when needed whereas, sun clips can be lost or broken.
Also, children should always have polycarbonate lenses in their eyeglass frames for safety. These lenses are made of a special plastic that is almost unbreakable the same material used in bulletproof windows.
Polycarbonate lenses provide 100 percent UV protection as part of their makeup, so your son will be safe wearing them. And polycarbonate Transitions lenses darken automatically in the sun to improve comfort. Dr. Dubow
[Page updated September 2014]