Exams to check for strabismus are done by an ophthalmologist or, in some cases, by an optometrist. The doctor can often tell that a child has strabismus just by looking at the child's eyes. It may be obvious that the eyes do not look in the same direction at the same time.

In an exam for strabismus, the doctor determines:

• Which eye is affected (or if both are affected).
• Which way the eye turns (in, out, up, or in some cases, rotating).
• How much the eye turns.
• When the abnormal turn occurs (all of the time or only when the child looks in a certain direction).
• Whether the child always uses the same eye to focus or switches back and forth, using one eye or the other.

The doctor may ask whether you have noticed the child squinting or closing one eye, tilting or turning his or her head, or bumping into things.

Some tests may also help the doctor decide whether the child has amblyopia, an eye condition also known as lazy eye in which one eye is not used enough for the visual system in the brain to develop properly. If strabismus occurs only some of the time, or if the child switches from one eye to the other for focusing, amblyopia is less likely to develop. Finding and treating amblyopia that results from strabismus early in life can prevent permanent vision loss. For more information, see the topic Amblyopia.

Early Detection

The U.S. Preventive Screening Task Force recommends screening to detect amblyopia, strabismus, and other vision problems in children younger than age 5 years.¹

No infant is too young for an eye exam by an ophthalmologist, and an exam should be performed whenever you have questions about the health of your child's eyes. The American Academy of Ophthalmology recommends that all infants should be screened by 6 months of age by a pediatrician, a family doctor, or an ophthalmologist.

Eye exams for children and infants