Genetics play a significant role in the development of comitant strabismus and elucidating the relevant mechanisms that cause it may lead to the development of new therapeutic options. The genetics of strabismus are complex and involve the interactions of multiple genes. This article reviews the progress that has been made in the understanding of the genetic causes of comitant strabismus including linkage studies that have identified a variety of candidate sites, RNA and protein studies that have identified genes with altered regulation, and a study that establishes a role for genetic imprinting in comitant strabismus.