When should I be concerned about my child’s crossed eyes?
It's normal for newborn babies to have eyes that cross or wander sometimes, especially when they're tired. However, if your child is older than 3 months of age, tell your doctor if you see your child's eyes cross or wander, even if it happens only once in a while. Also tell your doctor if your child often looks at you with one eye closed, or with his or her head turned to one side.
Source
Pediatric Vision Screening for the Family Physician by P Broderick (American Family Physician September 01, 1998, http://www.aafp.org/afp/980901ap/broderic.html)
Written by familydoctor.org editorial staff
Reviewed/Updated: 07/10
Created: 09/98