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Updated: Aug 19, 2026
Measuring Sensitivity to Viewpoint Change with and without Stereoscopic Cues
Published on: December 4, 2013
The critical period for susceptibility of human stereopsis
Sherry L Fawcett1, Yi-Zhong Wang, Eileen E Birch
1Retina Foundation of the Southwest, Dallas, Texas 75231, USA. fawcett@retinafoundation.org
Insights
Early visual experiences significantly impact stereopsis development. The critical period for susceptibility to visual anomalies extends from infancy through early childhood, affecting stereoscopic vision development.
Area of Science:
- Developmental neuroscience
- Ophthalmology
- Visual science
Background:
- Human stereopsis, the ability to perceive depth, is crucial for visual development.
- Anomalous binocular visual experiences, such as strabismus, can disrupt normal stereopsis development.
- Understanding the critical periods of visual development is essential for timely intervention.
Purpose of the Study:
- To determine the critical period during which human stereopsis is most susceptible to anomalous binocular visual experiences.
- To investigate the timing of this susceptibility in different types of strabismus.
Main Methods:
- Stereoacuity was measured in 152 children diagnosed with infantile or accommodative strabismus before age five.
- Developmental weighting functions were used to model the critical periods of stereopsis susceptibility.
- Data were analyzed for infantile strabismus, accommodative esotropia, and combined populations.
Main Results:
- For infantile strabismus, the critical period began at 2.4 months and peaked at 4.3 months.
- For accommodative esotropia, the critical period began at 10.8 months and peaked at 20 months.
- Combined data revealed susceptibility beginning shortly after birth, peaking at 3.5 months, and extending to at least 4.6 years.
Conclusions:
- Early anomalous binocular visual experiences profoundly impact stereopsis development.
- The critical period for stereopsis susceptibility is prolonged, extending through late infancy and early childhood.
- Interventions for visual anomalies should consider this extended period of susceptibility.
Purpose:
To define the critical period for susceptibility of human stereopsis to an anomalous binocular visual experience.
Methods:
Random dot stereoacuity was measured in 152 children with a history of onset of either infantile or accommodative strabismus before 5 years of age. In each of these populations and in the combined population, the critical periods for susceptibility of stereopsis are described using four-parameter developmental weighting functions.
Results:
In children with infantile strabismus, the critical period for susceptibility of stereopsis begins at 2.4 months and peaks at 4.3 months. In children with accommodative esotropia, the critical period for susceptibility of stereopsis begins at 10.8 months and peaks at 20 months. When the data are combined across the two populations, the critical period begins soon after birth and peaks sharply at 3.5 months but shows continued susceptibility to at least 4.6 years.
Conclusions:
An anomalous binocular visual experience during early infancy severely disrupts stereopsis, yet the critical period for susceptibility of stereopsis extends through late infancy and early childhood and continues to at least 4.6 years of age.
