Japanese companies Toko and Nikko produced the largest number of large military binoculars during WWII. That is because while the United States of America and Great Britain developed radar in the 1930s and 1940s, Japan continued to focus on binoculars. They felt so secure in their superiority in the optics of binoculars, that they thought they wouldn’t need radar. The Japanese navy equipped all their warships with naval binoculars, set on 90 feet high towers. The lenses could see up to 20 miles away and were designed to catch as much light as possible. The main purpose of these Big Eye Naval Binoculars was to spot Allied ships during World War II, but they also searched for the enemy’s aerial positioning.