Light
microscopy is the simplest microscopical method. The animal is placed on a
glass slide and can subsequently be observed through a glass objective.
Light microscopy produces a "flat" picture, viz. only the
structures in a narrow focus plane are visible. Hence, the picture is
strictly 2-dimensional. However, it is possible to obtain an idea about
about the 3-dimensional organization by gradually changing the focus
and photograph the object in different focus planes. One of the advantages
with light microscopy is that other associated structures such as muscles
and glands can be observed and that it is possible to observe live animals.