Pseudostrabismus is a common visual phenomenon where a child’s eyes appear crossed, even though they are perfectly aligned. This optical illusion often causes concern for parents who notice the appearance of an inward-turning eye (esotropia). Unlike true strabismus, which involves actual eye misalignment and requires treatment, pseudostrabismus is harmless and does not affect vision development. This false appearance is a normal part of infancy that resolves as the child grows.
Understanding Pseudostrabismus
The illusion of misaligned eyes is caused by specific features of a young child’s developing face. Infants often have a broad, flat nasal bridge, which makes the eyes appear closer together than they are. Small folds of skin, called epicanthal folds, also cover the inner corner of the eyes near the nose. These folds obscure the white part of the eye (sclera) on the nasal side.
When the eye looks toward the nose, the epicanthal fold covers more of the white area. This makes the colored part of the eye look as if it is turning inward, an effect most pronounced when the child is looking sideways. Since the eyes are physically straight and working together, the condition is purely cosmetic and involves no functional vision issues.
The Typical Resolution Timeline
Pseudostrabismus resolves when the infant’s facial structure matures through normal growth and development. The illusion diminishes as the nasal bridge gradually narrows and becomes more elevated. This change in bone structure pulls the skin tauter, causing the epicanthal folds to recede.
Most cases naturally improve and disappear between six months and 18 months of age. This resolution is directly tied to the child’s physical growth and facial development. If the appearance of crossed eyes persists past this typical age range, or if the misalignment seems constant, a professional evaluation is recommended to rule out true strabismus.
Differentiating False from True Strabismus
Distinguishing the benign illusion of pseudostrabismus from genuine eye misalignment is a primary concern for parents. True strabismus involves a lack of coordination between the eye muscles, causing one eye to turn in, out, up, or down while the other looks straight ahead. Parents can observe this difference at home using the Corneal Light Reflex Test, also known as the Hirschberg test, which requires a small flashlight.
Shine a light source directly at the child’s eyes while they look straight ahead. Observe where the light reflects on the surface of the eye. If the eyes are properly aligned, the reflection of the light (the corneal reflex) will be centered in the same spot on the pupil of both eyes.
If the child has true strabismus, the light reflection will be noticeably off-center in the misaligned eye compared to the straight eye. For example, if an eye is turned inward, the reflection will appear farther toward the outside of the eye. This observation helps gauge whether the appearance is a structural illusion or an actual misalignment, but it is not a substitute for a professional diagnosis.
Monitoring and When to Consult a Specialist
While pseudostrabismus requires no treatment, careful monitoring is necessary because the illusion can sometimes mask true strabismus. A child’s eyes may wander occasionally during the first few months of life as they learn to coordinate vision. However, persistent misalignment after three or four months warrants professional attention.
It is important to consult a pediatrician or pediatric ophthalmologist if the eye turn is constant or persists past the age of 12 months. Other warning signs include the child consistently tilting their head, frequent squinting or blinking, or difficulty tracking objects with both eyes. True strabismus, if left untreated, can lead to permanent vision loss in the affected eye, making early evaluation essential for protecting visual development.