Question
I have good news for you. It is entirely normal for a 1-month-old infant to intermittently cross her eyes, and the vast majority of small infants will do this. The eye crossing happens for a couple of reasons. First, in the womb she obviously had little on which to focus her eyes and, when born, her brain has to learn how to control her eyes to look at things she can now see. As with any learning experience, her brain doesn't get it right initially, and as a result you will periodically see her cross her eyes. Second, she is also in the process of strengthening her eye muscles, and one set of muscles might be stronger at one point than another set.
Answer
I have good news for you. It is entirely normal for a 1-month-old
infant to intermittently cross her eyes, and the vast majority of small
infants will do this. The eye crossing happens for a couple of reasons. First, in the womb she obviously had little on which to focus her eyes and, when born, her brain has to learn how to control her eyes to look at things she can now see. As with any learning experience, her brain doesn't get it right initially, and as a result you will periodically see her cross her eyes. Second, she is also in the process of strengthening her eye muscles, and one set of muscles might be stronger at one point than another set.
As long as her eye crossing is occasional and she can move both eyes in all directions, you have very little to worry about. If either eye is constantly turned in or out, or cannot move fully in all directions, or if you are still uncomfortable with what you are observing, talk to your daughter's health care provider about a referral to a pediatric eye specialist. One final comment: Although the eye crossing tends to get better after a few months as the brain and muscles develop, you may still notice some of the eye crossing happening again when she gets tireda very normal occurrence.
