No sooner do the eyes form than babies begin to perceive light in the womb. After birth, the eyes must learn to see. This is a gradual process. Right after birth, a baby cannot see much. In fact her vision is similar to that of a legally blind adult. But vision matures rapidly over the first few weeks of life, as the eyes receive stimulation in the form of thousands of images a day. The eyes are soon able to focus, and the brain integrates all the information coming through them. Remarkably quickly, a baby learns how to see.
The development of vision includes learning to focus on objects near and far, discriminating colors, and using both eyes to sec "in stereo." Once a baby can see well, she can begin to acquire visual knowledge. She learns what her parents look like, the difference between day and night, and how to tell far from near. The eyes must coordinate their movements so that they deliver similar information to the brain. Sometimes they look like they are wandering or crossed, but this can be a normal step in the process of developing vision. Occasionally the eyes become scratched or infected, but they usually heal quickly.
Eye Rolling and Wandering (Birth-3 Months)
Newborns are legally blind. If their vision were measured, it would be about 20/500. In other words, a baby can basically only see things that are the size and shape of a breast. This makes sense from an evolutionary point of view: it is all a newborn really needs to see. By six or seven months, vision improves to 20/50.
Newborns are also essentially color blind, able to see only black, white, and red. Again, this makes sense, as nipples on the human breast are red.
Vision improves over the first few months of life, as babies need to learn to see. With time, the eyes and brain begin to work together - the brain interpreting visual images from the two eyes "in stereo." At first, though, the brain accepts input from both eyes independently, so the eyes occasionally do funny things. The most common is eye wandering: one eye can roll in one direction while the other can be wandering off in an entirely different direction. This can be very disconcerting, but it usually stops by 4 to 6 weeks, when the brain and the eyes are much better at communicating. After that, the eyes will still occasionally wander or cross, but by 3 to 4 months, the crossing should be entirely gone.
Parents don't need to do anything - including worry - about occasional eye wandering in the first several weeks of life; it is entirely normal. A doctor does not need to be involved with random and occasional eye wandering seen in the first two months of life; this is completely normal. However, if one eye is not moving well, if the eyes look permanently crossed, or if the wandering eye movements are extremely frequent, then a doctor should check the child. This is true even if the baby is younger than eight weeks old. If you are ever in doubt, talk to your doctor. Because newborns normally have occasional eye wandering, tests do not need to be done. No treatment is necessary for normal eye wandering. As the baby learns to see, the movements will resolve. There are no complications of normal newborn eye rolling.
Crossed Eyes (Birth-12 Months)
There are three reasons why your baby may appear cross-eyed: (1) immature eye control causes the eyes to wander and occasionally appear to be crossed; (2) the eyes and nose are shaped in such a way that the eyes look crossed (but really they are not); or (3) the eyes actually cross (point toward the nose). Believe it or not, the third option - truly crossed eyes - is quite rare.
When babies look cross-eyed only some of the time, it is usually because their eyes randomly wander inward and point at the nose. This happens normally in the first few weeks of life, when the eye control is immature and the eyes and brain have not yet learned to work together. As your baby gets older, her eye wandering will become less and less frequent until one day it stops. If only one eye is crossed (or if it looks outward), and if this happens regularly beyond 2 to 3 months of age, then it is likely that one of the muscles responsible for controlling the eye movements is weak. This is called strabismus.
By far the most common reason for a baby to look cross-eyed is an optical illusion: if the eyes are widely spaced, if the bridge of the nose is wide and still undeveloped, or if the upper eyelids are particularly thick (callcd epicanthal folds), then the eyes can appear crossed even when they are actually perfectly aligned. This phenomenon is called pseudostrabismus. It is normal in infants of many ethnic backgrounds, especially Asian.
The best way to tell if your baby's eyes are not properly aligned is to look at the way light reflects on them. When light reflects at the same place on both eyes, they are aligned. When it reflects in different spots on the two eyes, they are not aligned. (Even though this test looks for how light "reflects," doctors refer to it as the light "reflex.")
Watch for a pattern to the crossing of the eyes. If your baby's eyes wander randomly, and this largely resolves by two months, then you needn't do anything. Even until three months of age, occasional eye crossing is acceptable.
If the crossing is an optical illusion caused by epicanthal folds, then there is nothing a parent can do. As the child grows, the eyes usually look less crossed.
An ophthalmologist (eye doctor) needs to see a baby if one or both eyes turn inward (or outward) consistently beyond two months of age or occasionally beyond three months. Sometimes it can be hard for a parent to tell whether the eyes are turned in or out, so if there is any doubt, you should have the baby seen by your doctor.
Your pediatrician or an ophthalmologist may do a cover/uncover test. This test checks eye alignment and identifies strabismus. In this test, an attention-getting object is held in the baby's line of vision. Then a cover is placed over one eye for at least two seconds and then removed. Normal eyes will continue to focus on the target. An eye that is truly crossed will move slightly when the other (normal) eye is covered. This crossed eye is trying to maintain focus on the object.
Tags: Babies and Toddlers
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