I'm browsing what the world has to offer me when I want to buy old (circa ’70s or ’80s) camera, e.g., a
Canon EX Auto QL. And I've noticed that most of them have camera lenses made in Japan. Was Japan the only country that was making camera lenses?
Japan was not the only country making cameras and lenses in the 1970's and 1980's but they had a huge market share. (they still do)
Before World War II most good cameras were made in Germany. Japanese companies started making copies of German cameras in the late 1930's and by the time the war ended, these Japanese cameras were very good quality. In the 1950's Japanese cameras became popular all around the world.
Here is a short list of camera companies and the country of origin:
Japan: Canon, Nikon, Pentax(Asahi), Ricoh, Olympus,
Germany: Leica, Rollei, Zeiss, Exakta, Minox, Pentacon, Praktica
Russia: Zenit, Lomo
USA: Kodak, Polaroid
(apologies for any brands I left out)
As to why Japan was/is so successful a lens-making nation, the summary in this excellent thesis answers your question pretty well:
Edit: in a nutshell, the thesis linked here identifies that Japan benefitted from considerable market protection put in place by the United States after the end of WWII, partly to keep Japan's cash flow going to service war debt. This meant Japan had a captive market of sorts (albeit willing) for several decades, long enough for their already established lens-making industry to really take off and become the global leader in most respects.
Additionally, Germany and Japan had enjoyed a rather unique productive trade and development relationship since about the turn of the century, and this definitely had an impact on Japan's lens design progress prior to the second world war. German firms actually had seconded some of their top engineers to work in Japan for years at a time in order to further the capabilities of both nations' industries. I don't have any references on hand for the above paragraph but Google will surely expand on this and I can do some digging if anyone is interested.
And to add "close East" remark. Soviet Union also make a lot of cameras and lens.
P.S. There is a lot of information in Russian language about old (and new) cameras and lenses, manufactured in ex Soviet Union and I just do not have enough time to translate it (moreover my English is broken :) ). If someone have interest of particular camera or lens will be glad to add translation for this item