Without the microscope, there would be no forensic science. At least it would look nothing like it does today. When father and son Dutch lens makers Zaccharias and Hans Janssen discovered that lining up several of their spectacle lenses in a hollow tube would magnify any object viewed, they could never have imagined how their discovery would change the world. When Anton van Leeuwenhoek, the Father of Microscopy, perfected this design and incorporated it into his studies of biology and medicine, he too never imagined the invisible world he would enter. Science and medicine would never be the same and the gateway to modern forensic science was opened.
The forensic science disciplines of blood analysis, firearm comparisons, trace evidence (hair, fiber, paint, etc.) examination, took mark interpretation, and even document examination regularly employ various types of microscopy. HERE are some examples.
The Crime Fiction Writer's Blog 
Frank Karl
March 18, 2013 at 9:07 am
Leeuwenhoek used a single lens which he ground from a tiny glass sphere.
Many other people, traveling from Robert Hooke to Dr. McCrone, to the Palenik father and son team, to Brian Ford and JG Delly and so many others have blazed the path of forensic microscopy. Much of the early days of forensic science were inspired by the fictional character Sherlock Holmes who made people wonder, “Why can’t that be done.”
If you’re an optical microscopist, you stand on the shoulders of giants.
Three Cheers for the Microscope!
Frank
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