Investigation of the onset and development of subjective acuity in normal young children

Abstract

Objective To investigate the onset age for measuring acuity and the evolution of subjective acuity in normal young children. Methods Using a cross-sectional study design, the monocular acuity of 264 normal young children was measured using the crowded HOTV video and the Closed-Circuit Operant Preferential Looking System (COPL) in random order controlled by computer.Influential factors were assessed.Data were analyzed with paired t test,independent samples t test,Pearson correlation, linear regression and logistic regression.Results In the study, young children began to recognize subjective visual symbols (26％) at 24 months.The measurement of subjective acuity in young children reached 100％ at 46 months.In 24-month-old children,the subjective acuity of the right eyes was 4.86±0.05 and it was 4.88±0.08 for left eyes.In 46-month-old children,subjective acuity was 5.0 for both right and left eyes.There were no significant differences between left eye and right eye,and also between males and females in subjective visual acuity.Subjective visual acuity was positive correlated with month age (r=0.526,P＜0.01).The regression linear equation between subjective visual acuity ((Y)) and month age (X) was (Y)=4.699+0.006X.According to logistic regression analysis,the education background of the mother (B=0.460,P=0.05) and the education background of the child (B=0.386,P＜0.01 ) were the significant influential factors.Conclusion This study suggests that the crowded HOTV recognition symbol system controlled by computer provided a method for investigating the onset of the subjective development of vision in young children.This study reveals that the subjective acuity of young children can be measured according to the age and cognition level of the child. Key words: Infant; Children; Optometry, subjective; Measurability; Development