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 than they otherwise would have with a properly fitted plastic frame. It's easy to spot a poorly fitted 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, OD, Massachusetts
Good point, Dr. Vachula. I appreciate your adding information to my already astute and insightful answer! Seriously, I was assuming the glasses 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 Liz DeFranco, our technical editor who is also an optician: Optical supplier Hilco distributes "soft" nose pads that are not silicone.
This type of pad is also commonly found on kids' glasses, where it appears to be a comfort bridge (one-piece, instead of individual nose pads), but is adjustable to fit tiny bridges. The material is also available
for larger size adjustable comfort bridges and nose pads
as well. All trained opticians should
be familiar with non-silicone nose pad options.]
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