Jill wrote:
I have just enrolled in school to be an optometrist and one of the first tasks I must do is figure out the scientific names for different frame types where can i find this info

ANSWER

Hello Jill,
There are several books out on the subject.  Look for any ophthalmic dispensing guide and usually the first chapter will have information on different frame materials.

Best of luck to you at school!
Dr. Donati

Diane wrote:
I have been wearing progressive eye glasses for a number of years and have always purchased them from my optometrist.  However, for the past few years, I have found the choice of frames to be limited and have not been happy with the choices I ended up making.   I have now changed my optometrist, due to relocation, but am finding the same problem with choice of frames at her establishment. My optometrist has prescribed “Progressive Additional, digitally surfaced’ lenses.  As these are very expensive, I want to be sure I get good frames that I am happy with.  I have always been dubious about going somewhere other than my optometrist (an optician or chain store for example) to purchase my glasses. Am I being unnecessarily cautious and can I be sure I would get the quality of lens I would get from my optometrist?

ANSWER

Diane,

I am very surprised that you have found that your optometrists do not have a good selection of frames.  Most optometrists have a very up to date and wide selection of frames for patients to choose from. You are right that glasses from an optometrist’s office will be of the highest quality.  They know your eyes the best so will know what type of lens will work the best for you.  If you have any problems with the glasses they would be able to diagnose and solve the problem quickly and efficiently.  I would not advocate getting glasses anywhere besides your optometrist.  However if you are going to get them somewhere else you do need to be extremely careful about what you are getting.  There are literally hundreds of different types of progressive lenses on the market today.  Some of these are thirty years old and will not work nearly as well as the new progressive lenses of today, which are called digitally surfaced, customized or free-form.  To ensure you are getting the best vision these newer types of progressive lenses give a wider field of clear vision and diminished distortions in the periphery of the lens. Of course lenses that are thirty years old will be a lot less expensive than the newest technology.  I hope this helps.

Dr. Carol Doman

Elaine wrote:
Hello,

The last time I got a new pair of glasses, I used the same prescription and I was not able to get used to the glasses. Everything looked curved at the edges.

My optometrist suggested that the “base curve” needed to be the same as my old glasses. That solved the problem.

No am I getting another new pair of glasses and they made the base curve the same, but said that it was effectively changed when it was put into the frames. They adjusted the frames to restore it, but I still can’t stand to wear the glasses. .

When I look at the computer I see an effect like the page is bulging towards me in places as my eye scans down the page.

My question: should a good optician be able to get this right the first time by using some objective comparison with my old glasses?   Should I be asked to go home and try them and go back 2 or 3 or more times to get it right? I find it too hard to try to describe what I am seeing.

Thanks,
Elaine

ANSWER

Hello Elaine,
I understand your description, and yes it does indeed sound like a base curve issue.  It would seem to me that the problem you are having is due to the fact that the base curve of the frame you have selected for your new glasses is different from that in your old ones.  That is the reason why the base curve of your lenses were “effectively changed” when they were put into the frame.  Some frame adjustment may help to improve the symptoms, but in the end you may just have to select a new frame that would allow the curve of the lenses to remain constant.  Make sure when you select your next frame that you tell them you are very sensitive to base curve changes.
Dr. Donati

Milen wrote:
I am 30 years old and I have been wearing glasses for about 15 years.
Recently I broke my old spectacles and bought a pair of new ones - almost identical frame as the previous one (thin titanium) just a smaller lenses.
It’s been two weeks with the new glasses and I experience pain in both my eyes as if I got a constant muscle strain. The prescription is exactly the same as the old ones. I have been going back to the optometrist two times - the first time she changed the alignment/fitting of the frame which seemed to help a bit but I still got the hurt in the eyes. The second time she adjusted them again thus making it worse! We tested the eyes and the lenses thoroughly but they are perfectly OK (same numbers). The optometrist is completely out of clue! What could be the reason for the pain and is it possible to damage my eyes in the long run?

ANSWER

Milen,
The fact that a change in the fitting of the frame can increase or decrease your symptoms is indicative of optical distortions caused by your new glasses. One of the causes of such a problem could be a change in the curvature of the anterior surface of the glasses (called base curve of the lens). Even if the numbers of the prescription are the same, a curve that is (often-times) flatter than the older one will create optical distortion than can induce your symptoms. The change of a base curve is made when it is determined by the manufacturing lab, considering the shape, the size and the profile of your frame, that the older one is not appropriate. Keeping the old one will lead to producing lenses that will be too thick or will be difficult to cut and edge to fit in the frame). Another possibility is that one of the lens was cut and edged too tight (or large) for the frame. Once inserted, a too tight lens will be compressed and optical distortions can occur from this.

During the manufacturing process, some waves can also be induced. If they do not affect the center of the lenses, they cannot be detected by the reading of their power.
There are no long term effects of these problems. This is discomfort coming from optical distortions. Once the glasses are removed, the eyes remain in perfect shape. If you continue to wear defective glasses, however, discomfort will continue and may cause headaches and malaise but it’s nothing irreversible.

Many thanks for this interesting question,
Langis Michaud
Associate professor – U de Montréal

Cynthia wrote:

I just got my new glasses. The frames hurt the side of my head.

They have tried to fix them but they still hurt. Could they be too small for my head? Do you think they could exchange them for a different pair?

ANSWER

Dear Cynthia,

This is a difficult question to answer without the benefit of seeing you with the glasses in place. If the glasses are pressing on the side of your head, they can be quite uncomfortable. Most frames can be adjusted so that the temples (the arms) only make proper contact with your head over and behind your ears. Sometimes it takes several attempts to get glasses properly adjusted – and in all honesty, some people are more skilled at this task than others. If several people have tried unsuccessfully to adjust your glasses, and you are still uncomfortable, you may need to choose another frame.

Dr. Smit