Asking a historian who invented the microscope might seem like a straightforward question. It might seem that way, but the true story of its invention is a lot more convoluted than you might think. Because when the first microscopes appeared sometime around 1590, they were marvels of science to be sure.

But the significance of the discovery was almost certainly lost on its creators. Few understood just how much of the world hid from us. A grain of sand, the width of a human hair, the often scratched flea; all existed at the fringe of perception. Before 1590, anything smaller than 0.1mm was effectively invisible.

Great thinkers throughout the ages debated the possibility of life beyond the limits of human understanding, but that is all they were; debates, theories, and clever arguments circulating among the learned people of the world. Mostly, such views attracted nothing but scorn and contempt.

The microscope changed all that. The person who invented the microscope changed the world.

But who invented the microscope? The short answer is that nobody really knows for sure. The long answer is that there is more than one contender with a strong claim.

Trying to decide which claim is strongest is far from an easy task. Fortunately, with several years of teaching social science under my belt, researching the question should be second nature. Filled with an optimism bred from long, lonely hours reviewing old, dusty history books, I set out to uncover the truth.

Optical intrusion

Few inventions exist in isolation from one another. The concept of magnification was understood centuries before the question of who invented the microscope had any meaning. In 1267, Roger Bacon, an English philosopher, noted that:

Such an observation was not all that unusual. Even our earliest ancestors must have noticed the way light tends to distort when it passes through water.

By 750 BCE, lenses made out of polished crystals or quartz were being crafted across Mesopotamia. Used primarily to start fires, these new tools soon spread across the ancient world.

Glassblowing arrived several hundred years later thanks to Syrian artisans. Neighboring civilizations such as the Greek and Roman Empires soon adapted the technology, creating lenses with sufficient strength to aid with reading.

Although simple affairs -- no more than a glass sphere filled with water -- they were cheap enough to see widespread use.

Lens flare

But the functionality of these "reading stones," was inadequate. The use of substandard glass notwithstanding, a globe filled with water is at best a cumbersome and imprecise tool.

It's little wonder that the Roman Emperor Claudius Nero chose to correct his shortsightedness with a concave emerald instead.

By the late 13th century, not long after Bacon began to explore the science of optics, the first spectacles started to appear in northern Italy. Again, the technology spread far and wide, and by the onset of the Early Modern Period, Holland had established itself as the spectacle-making capital of the world.

It’s no surprise then that asking who invented the microscope takes us to the Netherlands. It was here in 1590, in the Zeeland Capital of Middelburg, that one of three likely contenders crafted an object that was set to change the world.

Zacharias Janssen

Zacharias Janssen was born in the Hague between 1580 and 1585 but grew up with his sister Sara in Middelberg, the Netherlands’ second most important city.

How exactly it was that young Zacharias found himself involved in the making of spectacles is unknown. Optics was at the time a very secretive trade and what little records remain relating to Janssen’s father suggests he was a lowly peddler.

Regardless, in 1655, Dutch ambassador William Boreel set himself the task of discovering who invented the microscope. The instrument had by this point transitioned from mere novelty to a serious tool of scientific inquiry.

Boreel recalled that in 1610, he met a man from Middleburg claiming to have created the very first scope. He never gave his name though or at least, Boreel couldn't recall one if he ever did. Using the power fo his office, the Dutch ambassador instructed a local magistrate to begin an investigation.

As word spread, a spectacle maker by the name of Johannes Zachariassen came forward to press the claim. According to Johannes, it was his father, Zacarias, who invented the microscope as well as the telescope in 1590.

Hans Martens

Boreel was, for the most part, satisfied. At the time of the investigation, Zacarias was already 22 years in the grave and the memory of the chance encounter, 45 years in the past. Still, there were some who were less convinced that Zacarias had managed so stupendous a feat.

His age told against him for a start. Local records suggested a birthdate of 1580, but other dates given included 1585 and 1588. Such discrepancies were not uncommon during an age where record keeping was spotty and illiteracy rates high.

Still, his date of birth suggested that he was at best, 10 or 11 years old at the time he is said to have invented the microscope.

It is for this reason that many suggest that Zacarias’ father, Hans, either created or at the very least helped his son create the microscope.

One thing remained clear: the Janssens certainly were involved in the production of lenses with details of a 1595 Janssen microscope a matter of historical record. Indeed, the father-son duos would be unchallengeable if not for one slightly awkward fact.

They had a rather famous next door neighbor.

Hans Lippershey

Hans Lippershey was born in Wessel, Germany but like the Jansenns, he settled in Middelburg relatively early in his life. Setting himself up as a spectacle maker, it wasn’t until 1608 that he submitted a patent to the Dutch States General for an item he called a kijker or looker. We call it a telescope these days.

They denied his application. The device was, by this time, no secret and, consisting as it did of a single tube with two lenses at either end, it was reasonably easy to copy. Still, Lippershey received a sum of money for his work upon the requirement that he modify the device into a binocular arrangement.

In the absence of any evidence suggesting that Lippershey stole the design of the telescope from the Jansens, most historians are happy to credit him with its invention.

As to the question of who invented the microscope, the jury is still out.

Early 16th century microscopes were marvels of modern technology when it came to contemporary onlookers, but they were nevertheless incredibly crude instruments. They typically consisted of three tubes fitted with a bi-convex lens at one end and a plano-convex at the other.

Magnifications of between 3x and 10x were possible using this device.

In 1665, Robert Hooke published Micrographia. Magnificently illustrated, the book cataloged a series of observations that he had made while following the development and improvement of the microscope.

His detailed drawings of a bee’s stinger, fly eyes, fleas, and mollusk tongues made the book an instant best-seller. But the most significant scientific contribution stemmed from his observation of cell structure.

Indeed, Hooke coined the phrase "cell" after observing walls surrounding empty spaces in the structure of cork.

...and sinker

Incremental improvements undoubtedly occurred, but it was another Dutchmen, by the name of Antonie van Leeuwenhoek who took things to the next level.

His design featured a single spherical lens capable of magnifications of up to 500x. Using such a device allowed him to observe, for the first time in human history, bacteria. The year was 1683.

In keeping with the age’s paranoid obsession with scientific advantage, however, Leeuwenhoek refused to share the secret of his design. Over 100 years would pass before anyone observed bacteria again.

The pause was something of a pity really because, as we now know, bacteria is responsible for much human misery.

Today. Germ theory states that microorganisms can cause disease. These organisms, known as pathogens, can take many forms. Protists, bacteria, fungi, and viruses, all can invade a host and cause infection.

Mama miasma

The idea that tiny organisms caused sickness was first proposed in 1546 by the Italian physician Girolamo Fracastoro.

To say that his theory was not well received is something of an understatement. The perceived wisdom of the times dictated that illness stemmed from breathing in poisonous vapors known as miasma.

It made a certain sense; decaying matter certainly smelled foul enough. The unsanitary conditions of the era were also a contributing factor in the spread of disease. But they were not the direct cause of illness.

In 1762, another Italian physician, Marcus von Plenciz, attempted to revive the Germ hypothesis. Thanks in part to Leeuwenhoek’s stubborn refusal to share the secret of making high powered microscopes, however, Plenciz couldn't offer any proof. His speculation failed to change the consensus that disease sprang from miasma.

But the early 19th century ushered in one of the first genuinely effective medical treatments. Smallpox vaccinations, thanks to the work of Edward Jenner, brought a once dreaded illness to its knees.

By infecting a healthy specimen with the bovine version of the disease, knowns as Cowpox, the patient became immune from Smallpox. Alas, doctors knew only that vaccination worked; they had no idea how.

Nor were they able to replicate their success against other illnesses.

Although Louis Pasteur is probably the most famous microbiologist of all time, it was fellow scientist, Robert Koch who helped codify bacteriology.

Via careful experimentation, Koch was able to demonstrate that the bacterium Bacillus anthracis caused anthrax. His findings put an end to miasma theory once and for all.

Although improvements in optical instruments, continued, the 20th century also brought in fresh innovations. In 1903, German Chemist Richard Zsigmondy created the ultramicroscope, allowing scientist to view specimens below the wavelength of light for the first time.

The electron microscope arrived later. It was developed by Ernst Ruska, in 1938, after he realized that using electrons in microscopy could enhance resolution.

Today, the microscope remains a valuable tool. Forensic scientists examine the casings of bullets, physicians check bloodwork for telltale pathogens, and electron microscopes image virus strains both old and new.

In schools, students observe the cell structures of plants just as Hooke once did. And all over the world, objects as small as 0.2 microns come into the sharpest of focus.

Without the humble microscope, even the simplest of medical tests would be impossible. Without its clarity, we'd still be at the mercy of uncountable diseases.

So perhaps it doesn’t matter who invented the microscope. It’s enough to be thankful that somebody did. Who do you think has the most credible claim? Share your thoughts in the comments.