The prevalences of hard exudates, soft exudates, intraretinal microvascular abnormalities (IRMAs), and venous beading and their relationships to demographic and other characteristics were examined in a population-based study in southern Wisconsin. For participants whose age at diagnosis was less than 30 years and who were taking insulin (N = 996), hard exudates were found in 24.2%, soft exudates in 15.3%, IRMAs in 16.5%, and venous beading in 7.0% of the population. For participants whose age at diagnosis was 30 years or older and who were taking insulin (N = 674), hard exudates were found in 28.3%, soft exudates in 15.5%, IRMAs in 8.8%, and venous beading in 3.2%. For older-onset persons not taking insulin (N = 696), hard exudates were found in 9.4%, soft exudates in 5.4%, IRMAs in 2.6%, and venous beading in 0.9% of the population. The severities of the lesions were found to be consistently associated with longer duration of diabetes in younger-onset persons and the presence of proteinuria in older-onset persons.