(HealthDay News) -- Children should have an eye exam sometime before their sixth birthday, even if there are no unusual symptoms.

The U.S. Department of Health and Human Services says an appointment should be scheduled even sooner if the child has any of these warning signs:

  • The child's eyes are frequently crossed.
  • The child's eyes turn outward.
  • The child's eyes don't appear to focus together.
  • The child's eyes appear red, swollen or crusty near the eyelids.