While one can discern the major points that Foucault is making-namely, that a panoptic structure in education, the military, hospitals, and other groupings of individuals allows them to be disciplined without ceding power to one or a few other individuals-it is difficult to understand the finer points of his argument if one is not an expert in a number of specialized historical and sociological subjects. Despite these difficulties in understanding the specifics of Foucault's argument, his overall points are relatively easy to understand-that society is moving toward a generalized power structure that may be imposed with very little individual involvement, similar to that of an institutionalized population such as a prison or hospital or boarding school. These overall ideas, of reducing "the number of those who exercise [power] while increasing the number of those on whom it is exercised," and the prediction that this type of discipline and social structure "was destined to spread throughout the social body" recur throughout the essay, even when Foucault's specific arguments confuse the reader. His examples of these structured organizations -- the military, educational system, etc.-changing their main purpose from negative (i.e., schools taking in orphans or delinquents) to the positive (i.e., schools teaching certain methods to all school-aged children...

He assumes a certain level of knowledge regarding subjects on which he is an expert, and does not fully explain these subjects for anyone who is not.
His general theory-that society is becoming governed by a structure as opposed to by an individual-is fairly easy to recognize; he reiterates this theory throughout the essay and gives examples that are relatively easy to translate (the hospital or mental institution, for example). However, Foucault's terminology and sometimes-rambling prose make the finer points of his argument difficult. Although there is no definite moment at which the essay becomes more difficult to understand, the first section which discusses the plague-stricken town and compares it to the institutionalization of society is definitely the easiest section to understand; when Foucault begins citing Bentham and other sources with whom the reader is not intimately familiar, the reading becomes much more difficult.

Foucault's general ideas regarding the control mechanism of a panoptic structure in society are evident; however, his finer points are more difficult to grasp.