The first microscope was created hundreds of years ago. In the passing centuries, microscopes evolved into powerful, precise tools that allow scientists to view tiny objects at a level of detail that seems unreal. There are a wide array of available microscopes, from the compound microscopes commonly found in high school science classrooms to powerful scanning tunneling and electron microscopes used by Nobel Prize winners.



Most historians agree that two Dutchman made the first microscope in 1590. Zaccharias Janssen and his son Hans were two eyeglass makers who experimented with putting multiple lenses together in a tube. They found that objects under the tube were greatly enlarged. Over the next hundred years, scientists Robert Hooke, Anton van Leeuwenhoek, and others further refined the work of the Janssens and used microscopes to examine insects, blood, and other items. Scientists have continued microscopes into the present day. Now, microscopes can show tiny particles that are unseen by the naked eye in extremely exact detail.

Microscopes operate on several principles. Most common microscopes have two different lenses. Viewers look through the ocular lens, also known as the eyepiece. There is another lens, called the objective lens at the end of the ocular lens. The objective lens is a sphere shaped lens located above the stage of the microscope. People place the object they want to examine on the stage and can adjust the lenses to bring the object into focus. Most microscopes have an adjustment knob for coarse focus and one for fine focus. Many microscopes have several objective lenses with different strengths for users to choose from. The lenses are arranged on a circular platform that can be rotated to have the different lenses put into place under the ocular lens. Microscopes also need a light source of some kind underneath the stage. Most commercial microscopes have a light bulb, but many high-end microscopes use lasers or electrons for illumination.

Microscopes have been used to make countless vital scientific discoveries. They are invaluable tools used in a variety of scientific fields that enable researchers to make discoveries that would be impossible with the naked eye.