Explore Microscopy

Visit and Understand the Unseen World Around Us

Trichinella spiralis cysts in muscle tissue, DIC

Why Microscopy?

Curiosity about the little things, and how they work. That’s why. 

Normally, human eyes cannot see anything smaller than about the width of a fine human hair. That is about 0.04 mm at a distance of 15 cm from your face. Without microscopes anything smaller would be a complete mystery.

Human red blood cells are way below the resolution limit of the unaided eye, so without microscopes we wouldn’t know blood cells existed, let alone understand how they work.  Actually, we wouldn’t know anything about cells at all!

Bacteria and viruses also are too small to be seen with the unaided eye, so we wouldn’t know about them either. Medicine would be primitive, and we would have no idea how to fight diseases like Covid-19. Or even what Covid-19 was.

Genetics would not exist as it does today. No genetic testing, no understanding of genetic disease, no CRISPR. No understanding of the actual mechanisms of heredity. No understanding of how information is transferred from generation to generation.

Geology and metalurgy would be primitive. Microscopes are used to understand the fine structure and properties that make materials work the way they do. Modern high performance metal alloys would be unheard of. You couldn’t build a car. No airplanes, either. Certainly no moon rockets.

No real understanding of the cosmos, since that requires telescopes and they are essentially the same technology. No pictures from Hubble. No Hubble, either.

No photography. The same lens technology that  photography uses makes telescopes and microscopes work, too.

Forget, too, about the computer, tablet or cell phone you are reading this on. Computer chips are manufactured using microscope optics. No TVs either.

Microscopes have given us a way to view of the world of the very small and allowed a multitude of life-changing discoveries. Microscopes are without a doubt the most important scientific instrument ever created.

Oh, yeah, it’s a great hobby, too!


Microscopes have been used for scientific investigations since the late 16th century, when the first compound microscope was made by Hans and Zacharias Janssen.

In 1667, Robert Hooke published his book Micrographia with his drawings of specimens he had examined with his compound microscope, including a thin slice of cork. The cork had rectangular sections, or chambers, that Hooke thought resembled rooms in a monastery called cells, so that was the name he gave to the cork structures. The name cell has been used ever since to identify the smallest living unit that can live on its own.

Later, in 1676,  Antony van Leeuwenhoek, using a single lens microscope of his own design and construction, discovered bacteria, many other microorganisms, and even saw his own sperm for the first time. Because of his many discoveries, Antony van Leeuwenhoek is considered the father of microbiology.

The image at the right is a recently fertilized Purple Sea Urchin egg, showing the fertilization membrane surrounding the egg, and  acting as a barrier to prevent additional sperm from making contact.

This photomicrograph was taken through an Olympus BH-2 microscope afocally (through the eyepiece) using a cell phone.

Recently fertilized purple sea urchin egg showing fertilization membrane preventing double fertilization
A large clump of ovarian adenocarcinoma cells from peritoneal fluid.


Microscopes are crucial for diagnosis and monitoring infections and changes in cells and cellular responses to many diseases, both malignant (cancerous) and benign (harmless). The microscopist is very often the first person to see indications of disease.

This image is of ovarian cancer cells (Adenocarcinoma) from peritoneal fluid. Wright-Giemsa Stain.


There are many uses for microscopes in industry. Light microscopes are used for inspection of manufactured parts, such as semiconductor wafers, for analyzing design conformity, failure analysis, and manufacturing consistency. They are used as aids for soldering operations in assembly and repair. Metalurgical microscopes are used to measure metal alloy consistency, quality and failure modes. Electron microscopes can be used for elemental, structural and failure analysis.

This image shows an old Alcatel telephone circuit on a silicon wafer.

Diatom Exhibition Circle by Klaus Kemp with Labels shown in darkfield illumination


Historically, and well before radio, television, and the internet, microscopes were used by some of the wealthier folks to display what are referred to as Exhibition Slides to their friends and guests . These are microscope slides made either to show some interesting fact or structure in a particular specimen, or as with this slide, an arrangement of specimens for purely esthetic pleasure – microscopic art if you will. This slide has a large number of different, individual diatoms arranged in a decorative circle, and was photographed in Dark Field.

The diatom arrangement is relatively new and was made by Klaus Kemp of England.


Microscopes are an indispensable tool in education. Many if not most of us have used a microscope of some kind in school to view something too small to be seen with the unaided eye. 

Whether a single hand lens, monocular, binocular, stereo, or now even  a digital microscope, these instruments open up a whole new world to students. The ability to examine an item or organism at a very detailed level helps students understand the structure and makeup of organisms and even everyday items. 

From the world of microscopic pond life, to the internal structure of plants, animals, and even cells themselves. Insects, flowers, fungi, pollen and spores can all be studied as well. The identification of rocks and minerals by their appearance under polarized light microscopy is possible, too. There is no practical limit to the number of things that can be studied using a microscope.

This photomicrograph of mitosis in onion epidermis  was taken through an Olympus BH-2 microscope with a a cell phone.

Onion Root Tip - Mitosis