History is written in the history books. The more significant the history, the more history books you are likely to have (Well, at least in some cases).
What about the history of vintage frames? Sure, there are some books. But most look at vintage eyeglasses decades at a time or cover certain periods when significant events happened.
What about the design changes within a lesser amount of years? Design differences by different brands during the same period? There isn't always much information availble in written form.

We were recently offered to acquire a large collection of antique eyeglasses from the 1920-1950s. They were collected over many years and were offered to us at a great price. Many types of numont glasses, rimway glasses (semi rimless glasses) in many shapes styles and sizes.
Today we'll be conducting a highly unscientific study regarding popularity of 2 screw numont glasses in the 1940's. Who were the popular manufacturers of these 1940's glasses frames? what percentage of the market share did they have? What type of 1930's glasses were the most common. We have a few hundred vintage frames in this collection and we set out to analyze the data
Why is this highly unscientific? Because we do not know if our data set represents what was really out there at the time. It is possible that a large precentage of this collection came directly from one specific company, or was purchsed from another collector who had a preference for a certain stlye or company, and does not represent the real history of eyewear.

We looked at 146 pairs of 2 screw numont 1940's glasses. The results are as follows:
American Optical: 101
COC: 8
Artcraft: 11
UOC" 2
Shuron" 8
Bausch & Lomb (B&L)" 6
Other: 10 pairs
As we can see here American Optical wins by a landslide! While it is hard to believe these numbers represent the true market share of 1940's eyeglass frames, we can certainly deduce that American Optical was the leader in optical manfacturing. This goes with the known history of AO being the largest manufacturer at it's time.
Also interesting is the intricate design of the nose bridges an the differences between the various vintage frames brands. While from far they may all look the same, a closer up look at the various different numont glasses tells a different story.
Here is the most popular American Optical Eyeglass Frame (66 Pairs)
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Next comes the runner up at 35 pairs, also by American Optical (35 pairs)

Next comes Artcraft at a far 3rd place (11 pairs)

Then comes Shuron (8 pairs)

Another kind of Shuron bridge:

Yet a 3rd Shuron pair:

This one is by BSO (Bay State Optical - 1 pair)

This one we aren't sure of the brand

Next is U.O.C

Next 2 are C.O.C


Next comes Bausch & Lomb. Surprisingly few of these as B&L was a large company .

Next one we can't figure out unfortunate because these are very detailed and art deco eyeglasses:

That's it for today. So while this may be highly unscientific, it does tell us a bit about the larger brands and fascinating intricacies of vintage eyeglasses