We reviewed a series of 426 case or rhegmatogenous retinal detachment due to idiopathic retinal break and characterized the age at onset using a vital statistics model, Weibull distribution. When cases were divided into groups based on the type of retinal break, the cumulative frequency of each group could be described by the model. The equatorial atrophic hole group showed a frequency distribution which starts at about 7.5 years, culminates at about 20 years and terminates at about 40 years. The tractional tear group revealed two distinct distributions depending upon refractive errors; the non-high myopic subgroup showed a distribution which starts at 30 years and peaks at 60 years, and the high myopic subgroup had a distribution which starts at about 15 years and peaks at about 40 years. The macular hole group showed a distribution which starts in the second half of the third decade and peaks at about 60 years. The findings are consistent with the view that pathomechanisms having differing time courses are responsible for the age distribution at onset of rhegmatogenous retinal detachment caused by various types of retinal break.