ROP in high-income countries now occurs, mostly in extreme low birth weight infants. In those countries, the incidence of ROP seems to have declined incrementally over the last few decades. But in middle-income-countries, high rates of premature birth and increasing resuscitation of premature infants, often with suboptimal standards of care, have resulted in a third epidemic of ROP. Improved maternal and neonatal care, ROP screening guidelines appropriate to middle-income countries, and wide-spread timely treatment are urgently called for to control this third epidemic.