In 1988, the ARCHIVES published the preliminary findings of the Multicenter Trial of Cryotherapy for Retinopathy of Prematurity (CRYO-ROP Study).1 Even 16 years later, I vividly recall the tremendous excitement generated by that report, for after more than 20 years of uncertainty, here at last was an effective treatment for one of the major causes of childhood blindness. This issue of the ARCHIVES contains the final results2 from the CRYO-ROP Study, which report the outcomes of those babies who were randomized to treatment in the 1980s and who are now teenagers at 15 years of age. This marks the end of the line for the CRYO-ROP Study so now is the obvious time to glance back to review the impact of this study and see whether the hope to reduce retinopathy of prematurity (ROP) blindness has been realized in the long-term. With reports of outcome at 1, 3.5, 5.5, 10, and 15 years, this study proffers a unique insight into acute-phase ROP, its natural history, response to treatment, and its long-term sequelae of those eyes that were treated and those that were not. The findings of the study are far too numerous to discuss in their entirety, but we have learned, for instance, that African American babies are less likely to develop ROP than white babies3; that the onset, progression,4 and involution5 of acute-phase ROP are all related more closely to postmenstrual age than neonatal events; and that eyes in the acute phase of ROP exhibit a high degree of interocular symmetry.6 A particularly important aspect of the CRYO-ROP Study has been to identify the prognostic value of clinical signs, thus the degree of retinal vascular development,7 the posterior zone of involvement,8 and plus disease8,9 are all very strong predictors of poor outcome. The comments so far are now so ingrained in our understanding that it is difficult to remember that this knowledge has all come from the CRYO-ROP Study.