Every major field of science has benefited from the use of some form of microscope, an invention that dates back to the late 16th century and a modest Dutch eyeglass maker named Zacharias Janssen. While extremely rough in image quality and magnification compared to modern versions, the Janssen microscope was nonetheless a seminal advance in scientific instrumentation.1
Around 1000 AD, the first device used to enlarge images was the reading stone, a glass sphere placed on top of reading material to magnify words.
Zeiss Optical Museum in Oberkochen 2
About 280 years later, SalvinoD’Armate created the first pair of eyeglasses.
In 1590, Zacharias and Hans Janssen, a father and son team of eyeglass makers, invented the first microscope when they realized that items appeared magnified when viewed through a tube with multiple lenses placed within. This discovery directly led the invention of the first compound microscope and telescope.
Historians are able to date the invention to the early 1590s thanks to Dutch diplomat William Boreel, a longtime family friend of the Janssens who wrote a letter to the French king in the 1650s detailing the origins of the microscope. He described a device that rose vertically from a brass tripod almost two and a half feet long. The main tube was an inch or two in diameter and contained an ebony disk at its base, with a concave lens at one end and a convex lens at the other; the combination of lenses enabled the instrument to bend light and enlarge images between three and nine times the size of the original specimen.
No early models of Janssen microscopes have survived, but a Middleburg museum has a microscope dated from 1595, bearing the Janssen name. The design is somewhat different, consisting of three tubes, two of which are draw tubes that can slide into the third, which acts as an outer casing. The microscope is handheld and can be focused by sliding the draw tube in or out while observing the sample, and is capable of magnifying images up to ten times their original size when extended to the maximum.1
Microscopes throughout the 1600’s
Micrographia, published in 1665, is a historic book written by Robert Hooke documenting his observations through different lenses. He was among the first to make significant improvements to the basic design.
Hooke’s microscope shared common features with early telescopes: an eyecup to maintain the correct distance between the eye and eyepiece, separate draw tubes for focusing, and a ball and socket joint for inclining the body. For the optics, Hooke used a bi-convex objective lens placed in the snout, combined with an eyepiece lens and a tube or field lens. Unfortunately, the combination caused the lenses to suffer from significant chromatic and spherical aberration, yielding very poor images. He attempted to correct the aberrations by placing a small diaphragm into the optical pathway to reduce peripheral light rays and sharpen the image, but this only resulted in very dark samples. So he passed light generated from an oil lamp through a glass filled with water to diffuse the light and illuminate his specimens. But the images remained blurred.1 Micrographia is the first scientific best seller and is credited for coining the term cell.
In 1674, a Dutch scientist, Anton van Leeuwenhoek made further improvements and created ways to produce a curvature for lenses used in microscopes. This provided magnifications of up to 270 diameters, enabling biological discoveries such as descriptions of yeast plants, bacteria, the circulation of blood corpuscles in capillaries, and study protozoan found in pond water.
Microscopes in the 18th & 19th Century
During the 18th century, the history of the microscope was filled with technical innovations which enabled the further production and improvements on microscopes. Microscopy became very popular among scientists.
In 1830, the prototype for the Compound Microscope was created when Joseph Jackson Lister created a way to reduce spherical aberration, known as the chromatic effect, by combining multiple weak lenses without blurring the image, as opposed to lenses with higher magnifications.
In 1872, the research director of the Zeiss Optical Works, Ernst Abbe, developed the Abbe Sine Condition, a mathematical formula that allows for maximum resolution in a microscope.
Modern Microscopes of the 20th Century & Beyond
The 1900’s brought the introduction of instruments allowing the image to remain in focus when the microscope changed magnification.
1903 marked the year Richard Zsigmondy invented a microscope, the ultramicroscope, which could study objects below the wavelength of light.
Thanks to the greatly improved resolution, contrast-enhancing techniques, digital imaging, fluorescent staining and much more have revolutionized such fields as chemistry, physics, biology, and microelectronics.
In 1925, Zsigmondy won the Nobel Prize in Chemistry.
By 1931, the electron microscope was invented. Whereas the microscopes previously invented used light to view objects, the electron microscope uses electrons which have a wavelength that is 100,000th that of light.
In 1932, the phase contrast microscope was invented by Frits Zernike. The phase contrast microscope enables colorless and transparent biological materials to be studied.
In 1953, Zernike won the Nobel Prize in Physics.
In1982, Heinrich Rohrer and Gerd Binnig invented the scanning tunneling microscope. This microscope enables the viewer to see 3D images of objects. This is the strongest microscope ever created.
In 1986, Rohrer and Binnig won the Nobel Prize in Physics.
Today, it is possible to perform real-time fluorescence microscopy of living cells in their natural environment, while in 1999 Intel and Mattel collaborated on producing the $100 Intel Play QX3 Computer Microscope (since discontinued), bringing the instrument into the consumer marketplace. And, in the spirit of the early pioneers of microscopic research, scientists at Florida State University have brought the field full circle, turning their advanced instruments on common everyday objects like that All-American staple, burgers and fries, detailing thin sections of wheat kernel, onion tissue, starch granules in potato tissue, and crystallized cheese proteins.1