Retinopathy of prematurity (ROP) is an eye disease that affects premature or underweight babies (babies who weigh less than 3 pounds at birth). Abnormal blood vessels grow in the retina, the light-sensitive layer in the back of your eye.

Light-sensitive cells in the retina that work best in darkness or dim illuminations.

Innermost layer of the eye containing light sensitive nerve cells and fibers connecting with the brain through the optic nerve and nourished by a network of blood vessels; receives image and sends it to the brain.

Measurement of the focusing characteristics of the eye to determine refractive error and the need for prescription glasses.