Emily Brandon
Newborns see relatively poorly at birth. Infant vision at birth is about 20 to 30 times worse than that of adults, according to Dr. Rick O. Gilmore, Associate Professor of Psychology, Pennsylvania State University. Babies also cannot see a many colors very well, especially blues and purples.
However, infant vision is specifically suited to the needs of a newborn. Infants can perceive light as demonstrated by the pupillary reflex because the pupil constricts when light is shined on it, but are slightly farsighted. Babies see objects best that are approximately 18 inches from their eyes, which turns out to be the distance at which most mothers naturally hold their child when nursing or cuddling. Scientists speculate that this match between a mother's instinct and newborn vision can help children to better learn the details of their mother's face.
The eyes of newborns as young as one week are usually attracted to look more at a moving stimulus than at a comparable stationary object. Infant eyes are also drawn to the contours of objects with little time spent inspecting the internal features of objects. Their eyes look almost exclusively at the outline of faces since they cannot yet detect the finer details of faces.
In the months following birth, cones, the parts of the eye that allow color vision, migrate toward the center of the retina, grow larger, and become more densely packed. This allows infants to see more details and in dimmer light, according to Dr. Bennett I. Bertenthal, Professor of Psychology and Computation Neuroscience, the University of Chicago. In fact, infants develop detail, motion, and color vision very rapidly over the first six months of life.
Around three months of age, infants begin to focus the lenses of their eyes in order to see objects at varying distances from the eye. Three-month-old children also prefer their mother's face to the faces of strangers on the basis of vision alone, which indicates that three-month-olds can see their mothers' faces at least well enough to identify them.
Even newborns will visually track a moving object, but around three or four months of age infants begin to track objects with both eyes in harmony. During this time period they develop convergence, the ability of both eyes to look at the same object at the same time. At around six months, they develop coordination, the ability of both eyes to follow a moving stimulus in a coordinated fashion.
After the first six months of life, development slows. However, it is important to realize that babies can have widely different rates of development during the first year of life and still end up with normal vision.
According to Dr. Velma Dobson, Professor of Ophthalmology and Psychology at the University of Arizona, "Infant visual acuity gets better quite quickly over the first six months, and then progresses much more slowly after that, not reaching adult levels until somewhere between ages three and five years, and there is som evidence that acuity improves even slightly more between five and ten years."
Emily Brandon is currently a reporter for Healthy Living Magazine in Utica, NY. She also conducts neurobiology research at the University of Rochester Medical Center in Rochester, NY
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