It is clear that there is a genetic component to development of POAG. There is consensus that the majority of POAG is inherited as a complex disorder. Linkage and association studies have helped identify loci involved but there is inconsistency between study results and much remains to be elucidated. Further work requires large-scale collaborative work involving numerous scientific disciplines and may focus on quantitative traits. Unravelling the genetic component of POAG might clarify the pathophysiology of the disease and greatly assist in treatment and prevention of visual loss of many thousands of individuals. The complex genetic etiology of POAG is proving a hard nut for genetic epidemiologists to crack but greater collaboration and improved statistical and technical developments mean that progress in this area is being made.