First invented in the 1500s, light microscopes have not changed dramatically in the intervening years. Today, while some light microscopes incorporate digital technology to capture and record what they make visible, most still rely on the same principles that early light microscopes used.
Essentially, light microscopes allow researchers to see objects that are not otherwise visible to the naked eye. They achieve this by illuminating a subject (usually kept on a slide) and focusing the light through two lenses. The first lens, called the objective lens, concentrates light from a bulb onto the object being observed, thus focusing it within the microscope’s tube. The second, called the ocular lens, works like a tiny magnifying glass, enlarging the focused image so that the human eye can see it.
Researchers can view smaller objects by using different lenses, which offer sharper focus (for smaller objects) as they grow rounder and looser focus (for larger objects) as they grow flatter.
About Renate Bernstein
During her various expeditions as a marine science research assistant, Renate Bernstein has analyzed data with light microscopes as well as computer imaging software. After serving as a cardiac nurse for two years in the 1970s, Bernstein enrolled in the University of South Florida to pursue degrees in Marine Science. Today, she holds a Ph.D. in the discipline.