A series of 1,000 consecutive routine eye examinations performed on patients over the age of 50 was evaluated with particular reference to the presence of idiopathic preretinal macular gliosis (IPMG). In this group, there were 64 patients with IPMG (6.4%), 13 (20%) of whom had bilateral IPMG. The large majority of cases (63%), however, had only minor visual disability as a result of this disorder.