Friday, September 16, 2011

Your Baby’s Senses (Part 4): Sight

By Jennifer Goldbronn, MAS, RD

Today, we’ll continue our series on infants' senses by sharing information about the sense of sight. First, we’ll look at some of the milestones related to visual development in the first 6 months of life and then we’ll answer 2 common questions parents have about their babies’ sight.

The First 8 Weeks

A baby’s vision begins to develop at birth and is dependent on normal function of both the neurological system and structures of the eye. Newborns can see black, white, and shades of gray and can focus well to about 8-12 inches; they can see longer distances, but they can’t control the muscles in their eyes that allow them to see distant objects clearly. Because they can only focus a short distance, much of their vision is blurred. However, practice makes perfect; babies improve their focus by first focusing on faces and then moving on to bright objects nearby. At first, newborns can focus for only a few seconds at a time, but by 8 weeks, babies can focus their eyes on their parents’ faces for longer periods.  The ability to focus is not the only thing needed for babies to see clearly. They must also develop "visual acuity," or the ability to see details. While most structures of the eyes are completely developed at birth, the visual parts of the brain are not fully developed.  Studies show that during the first month of life babies’ visual acuity is about 20/120 (The Smith-Kettlewell Eye Research Institute). What exactly does that mean? If given an eye exam (and they could read), they would be able to read the big “E” at the top of the eye exam chart only. This is about 6 times worse than a normal adult seeing 20/20.

2-4 months

By 2-3 months, babies are able to follow people or objects with their eyes, and by 4-months, babies begin to learn hand-eye coordination as they begin to reach for objects. Their ability to see details (visual acuity) improves as well; by 4 months, babies’ vision has improved to 20/60. Then, as babies learn to roll over, sit up, and pull up, eye-body coordination begins. Eye-body coordination is simply learning to control body movements within the world around them.  Babies’ peripheral vision becomes almost as good as that of adults by about 4-months old. One study using flashing lights as part of a test of peripheral vision in infants found that newborns oriented towards the flashing lights out to 30 degrees in their field of vision. As babies got older, peripheral vision improved until infants at 4-months old could see almost as far as adults do.

4-6 months

 “Two-eyed” or “binocular” vision begins by 4-5 months so that babies fuse what they see from both their right and left eyes into one image, allowing them to develop strong depth perception. By 4-5 months, babies also begin to see in full color! Imagine how exciting their world becomes. All of these visual skills continue to improve over time, and by 6-months, many babies have developed 20/20 vision as they are able to see images more sharply and in greater detail.

2 Common Questions about Infant Vision

Should I worry if my newborn is cross-eyed?
No! Young babies must learn to use their eyes together. They begin to practice this skill by following objects with their eyes as they learn how to track and use their eyes together. This takes neuromuscular control that babies must learn over time. By about 4-5 months most babies have learned to coordinate their eyes together and the crossed eyes should stop. You shouldn’t worry about a young babies being cross-eyed unless his eyes cross after 5 months of age; then you should contact an ophthalmologist.

How important is it for my baby to have black and white toys?
Many toy stores sell black and white toys, claiming that these encourage visual development of infants. While it’s true that infants prefer to look at high contrast (like black and white) images because they are the most visible to them, high contrast patterns are not the only ones babies can see. Babies can actually tell the difference between much subtler shades of gray and their sensitivity to contrast becomes 10 times better than at birth by only 9-weeks, meaning it’s almost as good as that of adults. It’s important to give babies the opportunity to see other colors (besides black and white) and their subtleties and to let them explore important objects such as your face, your hand or their own hands and feet.

References and Resources

Lewis TL, Maurer D. Multiple sensitive periods in human visual development: evidence from visually deprived children. Dev Psychobiol. 2005; 46: 163–183.

Children’s Vision Information Network:

American Optometric Association:

What Can My Baby See? The Smith-Kettlewell Eye Research Institute:

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