Objective:To develop an E-chart visual acuity recognition card suitable for children aged 2-4 years and to design a child-friendly gamified intervention method to improve the success rate, compliance, and parental satisfaction in visual acuity testing for this age group.Methods:A non-concurrent historical control study design was employed, involving 143 children aged 2-4 years and parents who attended the ophthalmology outpatient clinic of Renmin Hospital of Wuhan University from January to June 2023. The children were divided into the control group and the intervention group based on their appointment times. Both groups underwent binocular visual acuity testing using the E-chart visual acuity recognition cards. The control group received conventional visual acuity testing, while the intervention group was subjected to a child-friendly gamified intervention. The effectiveness of the intervention was assessed by comparing the success rate of visual acuity testing, examination compliance, and parental satisfaction between the two groups.Results:Finally, the sample size of the control group and the intervention group were 69 and 74 cases. The children in the control group was (3.06 ± 0.47) years old, with 36 males and 33 females; whereas the children in the intervention group was (2.99 ± 0.45) years old, with 38 males and 36 females. The parents in the control group was (29.37 ± 4.00) years old, with 24 males and 45 females; whereas the parents in the intervention group was (29.35 ± 3.50) years old, with 27 males and 47 females. The success rate of visual acuity testing in the intervention group was significantly higher at 63.5% (47/74) compared to the control group′s 34.8% (24/69), with a statistically significant difference ( χ2=7.45, P<0.01). The compliance of the children during the examination in the intervention group, categorized as no grade I cases, 19 gradeⅡcases, 21 gradeⅢcases, and 34 grade Ⅳ cases, was significantly higher than that of the control group, which had 17 grade I cases, 23 gradeⅡcases, 15 grade Ⅲcases, and 14 grade Ⅳ cases ( Z=4.61, P<0.01). In terms of parental satisfaction, the intervention group′s satisfaction score was (4.53 ± 0.56) points, which was significantly higher than the control group′s score of (3.74 ± 0.78) points, indicating a statistically significant difference ( t=-4.88, P<0.01). Conclusions:The child-friendly gamified intervention significantly improved the success rate and compliance of visual acuity testing in children aged 2-4 years and increased parental satisfaction. This intervention provides an effective solution for visual acuity testing in children aged 2-4 years.