Diabetic retinopathy(DR)and diabetic neuropathy(DN)are common and interrelated chronic complications of diabetes mellitus. With the rising global incidence of diabetes mellitus, early prevention and management of DR are of paramount importance, as it is a leading blinding microvascular lesion. Studies have demonstrated that DN, especially diabetic autonomic neuropathy(DAN), has an earlier pathological process than typical microvascular damage, and the benefits of intensive glycemic control on neuropathy emerge earlier than those on microvascular lesions. The pupil, an organ precisely regulated by the sympathetic and parasympathetic nerves, exhibits dysfunction that serves as a sensitive indicator of DAN, and the degree of pupillary dysfunction is correlated with the severity of DR lesions. This review summarizes the association between diabetes-related neuropathy and DR, focuses on investigating pupillary motility abnormalities induced by DAN and their underlying mechanisms, and analyzes the application value of pupillometry in the assessment of DAN and DR, thus providing novel insights for the early intervention of DR. Nevertheless, the standardization and validity of its clinical application require further in-depth research and verification.