loupe

noun2

1. •
   A magnifying glass, usually mounted in an eyepiece, often used by jewellers and watchmakers.

   • Pemulis owns stuff like philatelic forceps, a loupe, a pharmaceutical scale, a postal scale, a personal-size Bunsen burner […] — 1996
2. •
   A type of short-range binoculars used by surgeons and dentists.