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Updated: Jun 23, 2026
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An Automated Method for Assessing Visual Acuity in Infants and Toddlers Using an Eye-Tracking System
Published on: March 17, 2023
Accommodation, acuity, and their relationship to emmetropization in infants
Donald O Mutti1, G Lynn Mitchell, Lisa A Jones
1The Ohio State University College of Optometry, Columbus, Ohio 43210-1240, USA.
Summary
Infant accommodation, not defocus, appears to drive emmetropization. Refractive error at 3 months best predicts visual development, with accommodation playing a key role.
Area of Science:
- Ophthalmology
- Developmental Biology
- Pediatric Optometry
Background:
- Emmetropization is the process by which refractive error stabilizes during early childhood.
- Understanding the visual factors influencing emmetropization is crucial for early detection of visual impairments.
- Previous models suggested hyperopic defocus might drive emmetropization, but evidence in human infants is limited.
Purpose of the Study:
- To investigate the relationship between ocular accommodation, visual acuity, and the process of emmetropization in human infants.
- To determine the predictive factors for successful emmetropization by 18 months of age.
Main Methods:
- 262 infants underwent assessments of defocus (distance and near) using Mohindra and dynamic retinoscopy at 3, 9, and 18 months.
- Visual acuity was measured using preferential looking at the same time points.
- Cycloplegic retinoscopy was used to determine spherical equivalent refractive error.
Main Results:
- No association was found between refractive error change and defocus levels.
- Refractive error change was linearly related to accommodative response at both distance and near.
- Higher hyperopic defocus was observed in infants with poorer emmetropization.
- Early hyperopia and specific retinoscopy findings predicted emmetropization outcomes by 18 months.
Conclusions:
- Cycloplegic refractive error at 3 months was the strongest predictor of emmetropization by 18 months.
- Accommodation, rather than hyperopic defocus, appears to be a significant visual signal influencing emmetropization.
- Infants demonstrate accommodative accuracy across moderate hyperopic refractive errors, suggesting a complex emmetropization mechanism.
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