PURPOSE: The purpose of this study was to investigate the development of visual acuity (VA) and contrast sensitivity in children as measured with objective (sweep visually evoked potential) and subjective, psychophysical techniques, including signal detection theory (SDT), which attempts to control for differences in criterion or behavior between adults and children. Furthermore, this study examines the possibility of applying SDT methods with children.
METHODS: Visual acuity and contrast thresholds were measured in 12 children 6 to 7 years old, 10 children 8 to 9 years old, 10 children 10 to 12 years old, and 16 adults. For sweep visually evoked potential measurements, spatial frequency was swept from 1 to 40 cpd to measure VA, and contrast of sine-wave gratings (1 or 8 cpd) was swept from 0.33 to 30% to measure contrast thresholds. For psychophysical measurements, VA and contrast thresholds (1 or 8 cpd) were measured using a temporal two-alternative forced-choice staircase procedure and also with a yes-no SDT procedure. Optotype (logMAR [log of the minimum angle of resolution]) VA was also measured.
RESULTS: The results of the various procedures were in agreement showing that there are age-related changes in threshold values and logMAR VA after the age of 6 years and that these visual functions do not become adult-like until the age of 8 to 9 years at the earliest. It was also found that children can participate in SDT procedures and do show differences in criterion compared with adults in psychophysical testing.
CONCLUSIONS: These findings confirm a slightly later development of VA and contrast sensitivity (8 years or older) and indicate the importance of using SDT or forced-choice procedures in any developmental study to attempt to overcome the effect of criterion in children.
1Department of Optometry and Vision Sciences, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia; 2School of Optometry and Vision Science, University of Waterloo, Waterloo, Ontario, Canada
Corresponding Author: Susan J. Leat School of Optometry and Vision Science University of Waterloo 200 University Ave West Waterloo, Ontario Canada N2L 3G1 e-mail: firstname.lastname@example.org
Submitted: June 8, 2016
Accepted: May 3, 2017
Funding/Support: This article was presented at the following conferences: (SJL, FMA, ELI) “Development of Visual Acuity and Contrast Sensitivity in Children: Comparison of Sweep Visually Evoked Potential and Psychophysics,” Child Vision Research Society, The Netherlands, June 2011; and (FMA, ELI, SJL) “Development of Visual Acuity and Contrast Sensitivity in Children: Comparison of Sweep Visually Evoked Potential and Psychophysics,” American Academy of Optometry, San Francisco, CA, November 2010, #105983.
This study was supported by the following grants to ELI: Natural Sciences and Engineering Research Council, Canada Research Chairs, Canadian Foundation for Innovation, Ontario Innovation Trust; and by a scholarship for FMA from King Saud University, Saudi Arabia.
Conflict of Interest Disclosure: None of the authors have reported a conflict of interest.
Author Contributions and Acknowledgments: Conceptualization: SJL, ELI; Data curation: FMA, SJL; Formal analysis: FMA, SJL; Investigation: FMA, SJL; Funding acquisition: ELI; Methodology: FMA, SJL, ELI; Project administration: SJL; Resources: FMA, SJL, ELI; Supervision: FMA, ELI; Validation: FMA, ELI; Visualization: FMA; Writing – original draft: SJL; Writing – review & editing: FMA, SJL, ELI.
The authors thank Linda Lillakas for her help in preparing the figures and Trefford Simpson for discussions regarding signal detection theory.