Beyond the Naked Eye: Light Microscopes
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(Image Credit: Gianna Goldfarb)
January 31, 2024
Ela Selin Akgün
11th Grade
Işıkkent High School
What Are Light Microscopes?
Light microscopes are devices used in laboratories that operate based on the interaction of visible light with small objects and structures by providing magnified images. Compared to other microscope technologies, light microscopes have numerous benefits in terms of scope and versatility.
To illustrate, it provides a magnification of 10x to 2000x, the most ideal magnification settings for biological fields such as histology, and the microscopic study of tissues. This promising technology is used in multiple other fields such as micrology, medicine, and material science.
(Image Credit: Wikimedia Commons)
(Image Credit: Technology Networks)
How do they work?
Light microscopes (also referred to as optical microscopes) use various lenses to focus the light on the specimen, providing a magnified image. The light microscopes’ magnifying process is made up of two sub-levels: illumination and imaging systems. This progress differentiates the types of light microscopes as the number of lenses used changes accordingly.
These lenses are aligned to reflect and bend light to magnify the image properly. Simple light microscopes are made up of only one lens, providing lower-quality magnification. On the other hand, the compound light microscope, made up of two or more lenses, provides a higher-quality magnification resulting in bigger images.
The logic behind the system of compound light microscopes is that it visualizes the details of an object by reflecting a beam of light through a lens to the object. Later on, this light is condensed by the lens and reflected to the object. After the light reflected from the specimen is collected in another lens, it later reflects the visual information in the eyepiece lens to our eyes. In this process, the transparency of specimens plays a big role as they need to reflect light, which is why narrow and transparent specimens are used in the labs.
On the other hand, simple light microscopes use a magnifying glass that magnifies the object when held close. Since it does not provide a magnification that is more than 2x to 6x, it is used more in nonprofessional settings.
(Image Credit: Technology Networks)
What is Their History?
The history of microscopes goes as far back as the 16th century. The idea of magnifying objects began from the demand to observe astronomical objects in closer detail, causing the invention of the telescope; the actual invention of microscopes is accepted as late 16th century to early 17th century. Hans Janssen was one of the first people who attempted to construct a compound microscope. His son, Zacharias Janssen, also had attempts in the 16th century, but his microscope had limitations of magnifying until 10x. Galileo Galilei is deemed to be the first scientist to develop one, however, there are controversies surrounding this topic, as he had developed an idea that already existed, but was accepted as the inventor of the compound microscope.
Later on, Antony van Leeuwenhoek invented a simple microscope around 1670 that magnified up to 200x. He had made hand-made lenses that were better than the ones existing at that time. However, Robert Hook managed to develop the first microscopes similar to the ones we use today. He added features such as an illuminator, a stage to hold specimens, and finer focus controls. However, his version of microscopes had a flaw: they had blurry lines and rainbow-like distortions called chromatic aberrations. This was finally solved by businessmen Carl Zeiss and Ernst Abbe by adding a condenser lens and turning it into the modern version. In conclusion, there is no specific person to give credit to the light microscope’s invention, since its idea was conceived and developed by several notable scientists.
(Image Credit: Gianna Goldfarb)
(Image Credit: Gianna Goldfarb)
(Image Credit: Gianna Goldfarb)
Reference Sources
Mokobi, Faith. “Light Microscope- Definition, Principle, Types, Parts, Labeled Diagram, Magnification.” Edited by Sagar Aryal, Microbe
Notes, 23 May 2023,
https://microbenotes.com/light-microscope/.
Ockenga, Wymke. “A Brief History of Light Microscopy.” Science Lab | Leica Microsystems, 8 Sept. 2015,
www.leica-microsystems.com/science-lab/microscopy-basics/a-brief-history-of-light-microscopy/.
Saladin, Kenneth S., and Sara E. Miller. “Light Microscopy.” Biology Reference, 2006,
www.biologyreference.com/La-Ma/Light-Microscopy.html.
Schädler, Kevin. “An Introduction to the Light Microscope, Light Microscopy Techniques and Applications.” Analysis & Separations from
Technology Networks, 2 Sept. 2021,
Wollman, Adam J. M., et al. “From Animaculum to Single Molecules: 300 Years of the Light Microscope.” Royal Society Publishing, 1 Apr.
2015,
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