The front and back of the eyeball fuse together by week 10, and muscles start moving the eyes by week 12.4 Eye movements can be detected by ultrasound, and can reveal whether a baby is awake, asleep, or dreaming.5
Most infants are born with light blue or gray eyes. A baby’s eye color finalizes between 6 and 12 months old. The color is determined by the distribution of melanin in the iris. Melanin is the same pigment that gives skin its color. If the melanin stays at the back of the iris, then the eye will be blue. If the melanin is found all over the supporting tissue in the iris, then the eye will be brown.6