<P> The microscopic scale (from Greek: μικρός, mikrós, "small" and σκοπέω, skopéō "look") is the scale of objects and events smaller than those that can easily be seen by the naked eye, requiring a lens or microscope to see them clearly . In physics, the microscopic scale is sometimes considered the scale between the macroscopic and the quantum realm . Microscopic units and measurements are used to classify and describe very small objects . One common microscopic length scale unit is the Micrometer (μm) - one millionth of 1 meter . </P> <P> By convention, the microscopic scale also includes classes of objects that are most commonly too small to see but of which some members are large enough to be observed with the eye . Such groups include the Cladocera, planktonic green algae of which Volvox is readily observable, and the protozoa of which stentor can be easily seen without aid . The submicroscopic scale similarly includes objects that are too small to see even with any optical microscope . </P>

What unit of measurement is used for objects seen under the microscope