Opera glasses were introduced during 1823 in Vienna. They are popularly known as Galilean binoculars. Opera glasses are compressed and are a magnification device of low power. They are also known as theatre binoculars because they are used to watch the stage performances especially when the stage is far from the seats. Since they were traditionally used during opera performances, these glasses were called opera glasses. Modern day opera glasses are based on the famous lorgnettes of the 19th century and have ornamental designs.