These opera glasses/binocular charms are all Stanhopes — they each have a tiny peephole where you can see a microscopic photo.
Per Werner Nekes, Stanhopes are:
Microscopically reduced, transparent photographs on a magnifying glass, fitted into a decorative object. These magnified photographic images were named after the English politician and scientist Charles, Earl of Stanhope (1753–1816). He attached microphotographs (invented by John Benjamin Dancer around 1860) to the flat end of an 8-mm glass rod; this was then viewed, astonishingly enlarged, through the convex polished lens at the other end.They were placed in everything from pens to pipes, and come in a variety of shapes, like cameras and tiny hands holding spy glasses. The images included everything from the Lord's Prayer to naked ladies.
1. From Belle Epoque Dolls
2. From pinguim
3. From RubyLane