The history of the microscope begins with the invention of lenses, the first microscopes, to later use light sources to clarify microscopic structures, which were unknown to the men and women of that time. It was no longer enough to increase the size of the letters on the old folios, but rather it was desired to take a closer look at insects, crystals and vegetable fibers. With the compound microscope invented, piece by piece, and model after model, it was necessary to optimize microscopy techniques for the analysis of increasingly complex samples. As the microscope and the quality of the images obtained evolved, more doors and possibilities opened up in the field of medical, biological and nanotechnological research. The evolution of the microscope is the same evolution of the human eye to see what escapes its limited vision in microscopic fields. Appearance of lenses 710 BC The Nimrud lens, which was a convex disk of rock crystal, was used in the Assyrian empire to magnify images, and also to concentrate the Sun's rays for the purpose of lighting fire. 167 BC The Chinese invented a device, the first approach to immersion microscopy, which consisted of a tube filled with water and lenses to magnify the images. 1000 The first magnifying glass appears, which consisted of a glass sphere with which the readings were speeded up. Its inventor is unknown. 1021 Al-Haytham publishes his Book of Optics, where he relates light to vision and image formation, as well as describing how lenses work. XIII Century During the XIII century lenses were perfected until relative magnifications were obtained. What is known as simple microscopes was born. In that same century, more precisely in 1284, the Italian Salvino D'Armate invented the first glasses. Birth of the compound microscope 1590 The first model of the compound microscope appears, invented by two Dutch eyeglass makers: Zacharias Janssen and Hans Martens. Its creation served as inspiration for the development of the first telescopes, since its model had a tube through which light traveled, very similar to the one that current microscopes still maintain. 1609 Galileo Galilei invents a kind of microscope-telescope composed of concave and convex lenses with which he studied small objects, such as celestial bodies seen in the sky. 1619-1621 Dutch inventor Cornelis Drebbel designs his own microscope, assembling it with two convex lenses for the respective objective and eyepiece. 1625 Giovanni Faber coins this new 'microscope' image magnification artifact. It is then when the compound microscope begins to be talked about. That same year two Italian scientists, Francesco Stelluti and Federico Cesi, published the first illustrations observed under a microscope. 1645 The parts of the microscope: objective and eyepiece, are coined by Antonius Maria Schyrleus de Rheita. 1661-1664 In these years the illustrations of the tissues observed under a microscope progressed. Also, Henry Power designs the first model of transmitted light microscopy by placing the samples on thin sheets of glass. 1665 Robert Hooke observed the cells in a sample of cork, first coining the basic units of life. His work and illustrations are published in the book Micrographia. 1674 Antonie van Leeuwenhoek, although working with a simple microscope, developed lenses capable of magnifying the image 200 times its size. He also invented techniques to polish these lenses, with which he was able to observe and analyze blood, microbes and insects. Practically, Leeuwenhoek laid the foundations of microbiology. End of the 17th century In the last three decades of the 17th century the microscope was incorporating some features, such as a mechanism to control the light that illuminates the sample, two monoculars (a binocular), the microscope slide and a compound eyepiece (Huygens eyepiece) . The latter, the work of Christiaan Huygens, addressed the wave nature of light. Development of the compound microscope 18th century In this century, the conventional image of the microscope in teaching laboratories was forged. The tripod first appears, in 1725, thanks to Edmund Culpeper. Then came an achromatic objective, created by Jan van Deyl in 1770. And finally, came the revolver, in 1776 by Jeremiah Sisson, a kind of revolving wheel where various objectives are placed. 1830 Joseph Jackson Lister solves the problem of imperfect images caused by achromatic and spherical aberrations. To do this, he built a set of lenses separated from each other by a short distance, which, although their magnifying power was weak, could correct the images of the microscope. 1834 The polarized light microscope invented by William Henry Fox Talbot appears. 1840 The first approach to microphotography occurs, after Charles Louis Chevalier combines the operation of daguerreotypes with those of the microscope. 1846 Carl Zeiss founds the Carl Zeiss AG company, which manufactures industrial quantities of microscopes and optical instruments. 1850 John Leonard Riddell invents the first working binocular microscope. 1872 Ernst Abbe, the research director of the Carl Zeiss company, creates a mathematical formula with which he can calculate the maximum resolution of a microscope. In it, said resolution is related to the wavelength of light, laying the foundations of modern optics. Late 18th century Compound microscope lenses increase in quality, as do better light sources. Modern microscopy 1903 The ultramicroscope, invented by Richard Adolf Zsigmondy, appears, taking microscopy to new levels. 1931 Ernst Ruska and Max Knoll build the first transmission electron microscope (TEM), which uses beams of electrons rather than photons to visualize samples. 1935 Frits Zernike creates a phase contrast microscope that is capable of visualizing transparent bodies, such as cells, without the need to stain them. 1936 The scanning electron microscope (SEM) appears thanks to the invention of Manfred von Ardenne. 1957 The confocal microscope is invented by Marvin Minsky. 1981 The scanning tunneling microscope (STM) is invented thanks to Gerd Binnig and Heinrich Rohrer, with which it is possible to reproduce 3D images at atomic scales. 1986 The world of materials is revolutionized with the emergence of atomic force microscopy (AFM), thanks to the microscope invented by Gerd Binnig, Quate and Gerber. Present From 1990 onwards, new microscopes (for example, cryogenic ones) have been invented, all with the aim of further improving the resolutions achieved, as well as being able to work with increasingly complex samples inherent to active fields of research , such as those of nanotechnology, biomedicine and the physics of materials.