Optics have been around for a very long time. In fact, the origin of modern firearm optics stretch all the way back to the 17th century, when a civil engineer by the name of John R. Chapman designed the first telescopic scope. These were later used to some extent in the Civil War, and later more prominently in World War I and II. Today, optics are considered an invaluable part of any firearm—whether on the battlefield or for self-defense.
Here are five facts about optics that you may have missed.