After development of Robert Hooke's light microscope, early elements of the cell theory were proposed. The invention of light microscope made it easy to study the structure of microscopic cell. After deciphering the cell structure with the help of a light microscope the cell theory was proposed. The invention of microscope was a big break through in the scientific world as it enabled researchers to study the microscopic structure. Later, the microscopes were modified to study the cellular organelles and prokaryotic microorganisms.
Cell theory provides the foundation for the study related to cells such as molecular biology, cell biology, etc.