Light is an essential component for microscopic observation. But what is it? This question is so old and interesting that many renowned geniuses have attempted to answer it. The list includes Aristotle, Democritus, Ptolemy, Descartes, Newton, Huygens, Hooke, Maxwell, and Thomas Young, with his elegant double-slit experiment, through which he demonstrated the wave behavior of light, preceding Einstein’s postulate known as the photoelectric effect, which earned him the Nobel Prize in Physics, back in the year 1921. It was not until 2015 that the Carbone group succeeded in capturing the dual wave–particle nature of light in a transmission electron microscopy micrograph. Despite this, controversy still exists among physicists regarding how much we truly understand about light and its often-complex nature. The fact remains that whether refracted, reflected, or dispersed, in microscopy, it is important to understand its behavior in order to concentrate or scatter it through the use of lenses. It is also important to consider that it is the knowledge of light–object interactions that galvanizes the correct use of photons to properly observe samples under a microscope.