The article is devoted to the issues of assessing the technical state of insulators of the overhead power transmission lines and the review of implementing different methods and means of assessment. The reasons and needs for monitoring the technical state of the overhead power transmission line insulators are determined, the main types of insulator defects are described and an analysis of the statistics of their failures during operation is provided. A review of methods for inspecting defects in the overhead power transmission line insulators using modern automated monitoring systems is presented. Methods for recognizing the overhead power transmission line insulators and localizing their defects in the ultraviolet and visible spectra images are considered. Methods for processing images of insulators in the ultraviolet and visible spectra with the use of computer vision algorithms are described. © 2023 IEEE.