The investigators hypothesize that reducing the amount of light that reaches the eyes of preterm infants may be effective in preventing ROP. Although previous reports on the use of light reduction to the eyes of preterm infants in the nursery have produced conflicting results, there are sufficient reasons to believe that this strategy may be effective in reducing the incidence and severity of ROP. These reasons center on the role of light in the production of destructive free radicals. Supplemental oxygen produces the same free radicals, and the two mechanisms may be additive.