Eye Alignment in Infants

By 6 months of age, children should have normal binocular alignment. 1

Normal Development of Eye Alignment

Newborns and very young infants may show transient misalignment of the eyes, with small amounts of exotropia (outward turning) being most common during the first month of life 2
Most infants achieve orthotropic (straight) eye alignment during the first month, though accurate convergence (ability to focus both eyes inward) typically does not develop until around 6 weeks of age 2
By 3-4 months of age, binocular vision, accommodation, and depth perception begin to develop 3
Eye movements mature from jerky and inaccurate to smooth by 6 months of age, at which point children can maintain fixation and adjust their eyes to new visual fields without error 3
By 6 months of age, normal binocular alignment should be established, as recommended by the American Academy of Ophthalmology's Preferred Practice Pattern 1

Persistent misalignment after 6 months of age is abnormal and requires evaluation, as it may indicate strabismus that can lead to amblyopia (lazy eye) and impaired binocular vision 1
Children with esotropia (inward turning of the eyes) that persists beyond 6 months of age are at increased risk for developing amblyopia and poor stereopsis (3D vision) 1
Infantile esotropia that is constant and presents before 6 months of age is unlikely to resolve spontaneously, while intermittent or variable esotropia measuring less than 40 prism diopters may resolve by age 1 year 1
Early detection and management of eye misalignment is critical because binocular vision can degrade rapidly in young children, resulting in suppression and abnormal visual development 1

Primary care providers should perform vision screening of newborns and infants under 6 months of age 1
Screening should include red reflex testing, external inspection of ocular structures, pupillary examination, and assessment of fixation and following behavior 1
The standard assessment for children younger than three years is to determine whether each eye can fixate on an object, maintain fixation, and follow the object into various gaze positions 1
Any persistent eye misalignment noted after 6 months of age warrants referral to an ophthalmologist 1

Research shows that surgical alignment for congenital esotropia should be accomplished by 2 years of age to attain the highest yield of binocular function 4
Duration of misalignment, rather than age at alignment or age at onset, is a significant factor in determining stereopsis outcomes 5
Patients who develop stereopsis (3D vision) have more stable long-term alignment and are less likely to develop complications like dissociated vertical deviation 5
While alignment by 2 years has established benefits, there is limited clinical evidence that alignment before 6 months yields significantly better binocular outcomes than alignment by 1-2 years of age 6

Transient misalignment in the first few months is common and should not be immediately interpreted as pathological 2
Poor cooperation or disinterest from an infant can mimic poor vision response during testing, so assessment should be performed when the child is awake and alert 1
Children with underlying medical or genetic conditions (prematurity, Down syndrome, cerebral palsy) are at higher risk for eye alignment problems and should receive comprehensive ophthalmic examination soon after diagnosis 1
Instrument-based vision screening (photoscreening, autorefraction) can be valuable in detecting amblyopia risk factors by age 1 year but does not directly measure visual acuity 1