Lenses are most important part of the microscope.  In history, these began as clear convex-shaped glasses that people used mainly to look at small things. The most popular use magnifying glasses had was as vision aids, where people placed them on top of reading materials to make them easier to read. In the late 1200s an Italian names Salvino D’Armate was said to have invented eyeglasses, the first time magnifying lenses were placed in frames and could be worn around by people.

Three hundred years later, the father and son Zaccharias and Hans Janssen began experimenting with the eye glasses that they were making in their shop. They placed several lenses in a tube and discovered that objects look larger seen through the end of the tube with the help of the primitive lenses. This became the first model of both the compound microscope and the telescope.

In 1665, Robert Hooke came up with the term “cells” while studying a piece of cork through the early microscope. This is because of the small pores resembling rooms that he saw that made up the cork. Hooke’s discoveries about cells however, were limited to cells of non-living things.  It was Anton van Leeuwenhoek who began studying small living organisms in water and blood, as well as insects, yeast and other tiny objects. Leeuwenhoek invented the first single lens microscope, polishing lenses to a curvature that allowed it a magnification of 270 diameters, making it the best microscope during the late 1600s. He is also the first person to describe bacteria, earning him the title “Father of Microscopy”.

A lot of people exerted effort in improving the optical microscope as we know it.  One of these early inventors of the microscope was Joseph Jackson Lister, who found a way to use several weak lenses to give better magnification without blurring the image in 1830. Ernst Abbe, another significant contributor to the invention of the microscope, came up with the “Abbe Sine Condition”, a mathematical formula for the maximum resolution in microscopes possible, in 1872. Richard Zsigmondy developed the ultramicroscope in 1932. This kind of optical microscope was designed to be able to study objects below the wavelength of light. Following this invention was the first phase contrast microscope by Frits Zernike, which was useful because it enhanced the light contrast so that it would be easier to distinguish between the transparent and colorless objects. Phase contrast microscopes are today used primarily to study biological tissues, both on glass slides as well as in petri dishes in inverted microscopes.  If phase contrast microscopy is used, then specimens do not require staining.

Often, staining will affect the still living tissue on the slide, so it is not always the best way to image the specimen tissue.
Another type of microscope was invented in 1931 by Ernst Ruska, for which he won the Nobel Prize in Physics in 1953. This was the electron microscope, which used electrons instead of light to view objects. This worked through speeding up electrons in a vacuum so that the wavelengths of those electrons become a hundred-thousandth of the wavelength of white light. Electron microscopes are used to view objects as small as the diameter of an atom.
Electron microscopes vary in the way they work.  The scanning electron microscope (SEM) looks at the surface of most objects by scanning it and measuring the reflection. Transmission electron microscope (TEM) works by having electrons go past the surface and through the object to enable people to see things not normally seen by the naked eye.

In 1981, Gred Binnig and Heinrich Rohrer invented the scanning tunnelling microscope which allows people to see three-dimensional images of an object to its atomic level which makes it the most powerful microscope to date.
Over the centuries, the history of the microscope and optical lenses provide an interesting story for us to read.  These early inventors and fathers of microscopy have contributed greatly to the modern world in which we live in today.  We are indebted to them for their ingenuity and engineering feats invented so long ago.  The history of the microscope will forever remember their achievements.