Q.: I recently purchased a pair of plastic frame glasses with Transitions progressive lenses (yes – expensive!). I love the glasses, but I did not realize that plastic frames stretch out so easily. I had them adjusted once in the first month, and they immediately stretched back out and won’t stay on my face if I lower my head. I was told that adding spring hinges may help. Can you give me a price for adding spring hinges to glasses that are, otherwise, intact? Thank you!
A.: We are getting this request a lot. Let us go through some basic questions so that we can get you a reliable and permanent solution to your problem.
If the frames were properly fitted to you, that is, the size was chosen correctly, the distance across the frame front, i.e. 46 or 48 or 50 frame size, is the distance between the two hinge screws and should be wide enough that the temple arms go straight back to the tops of your ears without touching the side of your head.
Now if the frame is too small for your head, say it is a 46 and you needed a 50, then the temple arms will go back towards your ears, and press against the sides of your head at the edge of your face, stretching out the frames. Some Opticians will try to adapt for this by bending the temple arms out, and then curve them back in. This sometimes works, but it produces other problems where the end of the temple tip goes over your ear.
There is an installation called a “French Stop” where two adjustable screws are set into the face of the frame front to provide an adjustable stopping point for the shut-face of the temple arm tang head. This provides a substantial amount of adjustment to the resulting width of the temple arms without bending them.
If your frame front is in fact correct in width, the second number written on the frame should be your nose bridge size, and it will be 16, 17, 18 or such, and if the arch does seem to fit your nose bridge correctly, it should be comfortable and support your glasses so that the Optical centers of your lenses are directly in front of the center of your eyes.
That only leaves the problem of the temple arm length and the arch at the end.
The length should be written on the inside of the right interior flank of the temple arm and will be a number like 140, 145 etc. This should result in a temple arm that goes back to the top of your ear where it joins the side of your head, like where you would place a wood pencil on your ear to hold it, and clears the high spot before it starts to curve. The curve should then be a correct adjusted copy of the back arch of your ear.
If all of these factors are correct, the frames should perform for you correctly and remain in place during normal activities.
Spring hinges are intended to provide a safety zone of arching area where the temple arm can spring outward in response to removal from the head or removing a cycling helmet, or a sudden jolt from the side while wearing them, but they are limited in their usefulness for gripping.
Cable ends are the coil of springy cable that curves like a letter “C” at the end of the temple arm and grips the backside of your ear. Cable ends are the solution for vigorous activity like horseback riding, tennis etc. to provide positive retention of eyeglass frames in place on your face.
Send in your plastic frame glasses today for repair!