I can think of many reasons why someone would purchase Opera Glasses- since they are small and can fit easily into a purse or a pocket, going to the ball game, a concert, spying on your neighbors, watching birds from the comfort of your armchair.
A site we recommend is Fine Opera Glasses (.com) offers an excellent selection of Opera or Theater Glasses.
A little history: (From their website)
Like many inventions, Opera Glasses came into existence as a result of a long line of inventions, and further improvements upon those inventions. The process started in the year 1608 when a Dutch optician by the name of Hans Lipperhey developed the first pair of binoculars with a magnification capability of X3. Less than a year later, a well known inventor and philosopher by the name of Galileo developed what became known as the Galilean telescope which had a magnification capability of x30 which allowed him to search the heavens.
Advertisements were first found for opera glasses and theater binoculars in London as early as 1730 in the form of a long collapsible telescope. The “Opera Glass” as it was referred to; was often covered in enamel, gems, ivory, or other art and paintings.
For almost 100 years opera glasses existed merely as telescopes. In Vienna in 1823 the first binocular opera glasses and theater binoculars began to appear. They were two simple Galilean telescopes with a bridge in the center, each telescope focused independently from the other by extending or shortening the telescope until a desired focus was achieved, which was useful, yet very cumbersome.
Two years later in Paris, Pierre Lemiere improved on this design and created a center focus wheel. This allowed the focusing of both telescopes together. After this development, opera glasses and theater binoculars grew in popularity because of the superior view they facilitated in opera and theater houses. The beautiful design of the glasses themselves also added appeal to the opera-going crowd. By the 1850’s opera glasses and theater glasses had become a must-have fashion accessory for all opera and theater-goers.
Today, in modern opera glasses, the design Galileo implemented in his first telescope 400 years ago is still in use today, although there have been many improvements to the design over the years. Opera glasses offer a front row view, regardless of where you seat is. Opera glasses and theater binoculars now come in many varieties. There are opera glasses with chains, with handles, and lights for reading your program discreetly during the performance. They also come in many materials, styles, and colors to fit each personality.