Retinopathy of prematurity (ROP) is an ophthalmic disorder that arises in premature infants, particularly those born before 32 weeks gestation, or who weigh less than 1,500 grams at birth. In many children, it is mild and presents no problems, but can also be severe and lead to blindness. In the 1940s, it was the leading cause of blindness in children in the US and, unfortunately, it still remains a leading cause of blindness in children worldwide.