14th century:spectacles first made in Italy

1590:Two Dutch spectacle-makers and father-and-son team,Hans and Zacharias Janssen, create the first microscope.

1667: Robert Hooke's famous"Micrographia"is published, which outlines Hooke's various studies using the microscope.

1675:EnterAnton van Leeuwenhoek, who used a microscope with one lens to observe insects and other specimen. Leeuwenhoek was the first to observe bacteria. 18th century: As technology improved, microscopy became more popular among scientists. Part of this was due to the discovery that combining two types of glass reduced the chromatic effect.

1830: Joseph Jackson Listerdiscovers that using weak lenses together at various distances provided clear magnification.

1878:A mathematical theory linking resolution to light wavelength is invented byErnst Abbe.

1903: Richard Zsigmondy invents the ultramicroscope, which allows for observation of specimens below the wavelength of light.

1932:Transparent biological materials are studied for the first time usingFrits Xernike's invention of the phase-contrast microscope.

1938:Just six years after the invention of the phase contrast microscope comes the electron microscope, developed byErnst Ruska, who realized that using electrons in microscopy enhanced resolution.

1981:3-D specimen images possible with the invention of the scanning tunneling microscope byGerd BinnigandHeinrich Rohrer.