Infants born early who are in the neonatal intensive care unit will be included if they meet national guidelines for retinopathy of prematurity (ROP) screening exams. Informed consent will be given to the parent(s) or legal guardians. 1.5-2 ml of blood will be drawn from a vein when the child is enrolled in the study and may be drawn again if the child requires treatment of eye disease. A cheek swab will also be obtained. These biologic samples will be shipped overnight to the University of Utah for genetic analysis. Analysis will determine if a change in gene expression causes retinopathy of prematurity. Infants enrolled in the study will be followed clinically per established ROP screening guidelines. They will not require additional study exams.