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Updated: May 2, 2026
Author Spotlight: An Automated Method for Assessing Visual Acuity in Infants and Toddlers Using an Eye-Tracking System
Published on: March 17, 2023
Normative visual acuity in infants and preschool-aged children in Sydney
Jody F Leone1, Paul Mitchell, Annette Kifley
1Discipline of Orthoptics, The University of Sydney, Lidcombe, NSW, Australia.
Insights
Visual acuity (VA) norms in children aged 6 months to 6 years improve with age. Lower socioeconomic status is linked to poorer VA, highlighting the need for population-specific norms and the Amblyopia Treatment Study (ATS HOTV) protocol for vision screening.
Area of Science:
- Ophthalmology
- Pediatric Medicine
- Public Health
Background:
- Establishing normative visual acuity (VA) data in children is crucial for identifying visual impairments.
- Previous studies have varied in methodology and population, necessitating updated, population-based data.
Purpose of the Study:
- To determine age-specific, population-based normative visual acuity (VA) values for children aged 6 months to <72 months.
- To compare different VA measurement protocols in a pediatric cohort.
- To investigate associations between VA and socioeconomic factors.
Main Methods:
- Monocular VA was assessed using the Amblyopia Treatment Study (ATS HOTV) protocol, ETDRS/HOTV logMAR charts, and Teller Acuity Cards II (TAC II).
- Children with significant refractive error or ocular disease were excluded from the analysis.
- Data were collected from participants in the Sydney Paediatric Eye Disease Study.
Main Results:
- Visual acuity improved significantly with age across all tested methods (p < 0.0001).
- Mean VA using ATS HOTV improved from 0.13 logMAR (<36 months) to -0.01 logMAR (66 to <72 months).
- Lower socioeconomic status was associated with poorer VA, with factors like home ownership and parental employment showing statistical significance.
Conclusions:
- Normative VA in children increases with age, and results vary depending on the testing protocol used.
- The findings underscore the importance of establishing test-specific VA norms for diverse populations.
- The ATS HOTV protocol is recommended for vision screening due to its lower false positive referral rate.
Purpose:
To provide population-based normative visual acuity (VA) by age, in children participating in the Sydney Paediatric Eye Disease Study aged 6 to <72 months.
Methods:
Monocular VA was measured using the Amblyopia Treatment Study (ATS HOTV) protocol (24 to <72 months). Some children were also tested using linear ETDRS or HOTV logMAR VA charts (30 to <72 months). If unable to perform recognition acuity, the Teller Acuity Cards II (TAC II) was performed (6 to <42 months). Children with significant refractive error or ocular disease were excluded.
Results:
Improvement in VA with age was shown on all three vision tests (all p < 0.0001). Mean VA using ATS HOTV (n = 836) was 0.13 logMAR (6/8) at <36 months, which improved to -0.01 (6/6) at 66 to <72 months. Mean ETDRS/HOTV (n = 399) VA was 0.26 logMAR (6/11) at <36 months, which improved to 0.1 (6/7.5) at 66 to <72 months. Mean monocular TAC II (n = 442) was 5.7 cycles/degree (0.72 logMAR) at 6 to <9 months and improved to 12.4 cycles/degree (0.38 logMAR) at age 30 to <33 months. Associations with ATS HOTV VA included prematurity (p = 0.027) and socio economic status (SES) factors such as home ownership (p = 0.039) and employment of one (p = 0.019) or both parents (p = 0.003).
Conclusions:
VA norms in children improved with age and were different according to the VA test used. Low SES was associated with poorer VA, supporting the need for test specific VA norms to be established for different populations. The ATS HOTV appears to be the best test to use for vision screening due to its lower false positive referral rate.
