What Should a Child’s Normal Visual Acuity Be?

High-tech products are becoming increasingly prevalent. Children now frequently use electronic devices for learning. Prolonged screen time—especially extended viewing of television—can significantly harm children’s eyes, gradually reducing their visual acuity and increasing the risk of myopia. Visual health in children is a major concern for many parents. So, what constitutes normal vision for children?

What Is Considered Normal Vision in Children?

The normal range of visual acuity during pediatric health examinations varies according to age. Children can typically undergo vision screening starting around age 3. At approximately 3 years old, visual acuity is usually about 0.6; by age 4, it generally reaches 0.7–0.8; at age 5, it is approximately 0.8; and by age 6 or older, most children achieve visual acuity near 1.0—very close to that of adults.

If a child’s visual acuity is markedly below the expected standard for their age group—or if there is a difference of two or more lines between the two eyes—this warrants prompt attention and a comprehensive ophthalmologic evaluation to assess refractive status. If myopia is diagnosed, corrective eyeglasses are indicated. In cases of high hyperopia or astigmatism, amblyopia may coexist; such children require optical correction (glasses) and possibly additional amblyopia treatment and visual training.

Standard vision assessment includes both distance and near vision testing.

Distance vision testing: In China, the Snellen chart and the logarithmic visual acuity chart (developed by Professor Miao Tianrong) are commonly used. During testing, the examinee sits 5 meters from the chart, with the 1.0 line (Snellen) or 5.0 line (logarithmic chart) aligned horizontally with the eye. Each eye is tested separately—right eye first, then left—with testing proceeding from top to bottom. The examinee quickly identifies the orientation of the optotype’s gap (e.g., up/down/left/right), and the smallest line correctly identified is recorded. Normal visual acuity is defined as 1.0 (Snellen) or 5.0 (logarithmic). When visual acuity falls below 0.1, the examinee may gradually move closer to the chart; visual acuity is then calculated using the formula: 0.1 × d/5, where d is the distance (in meters) at which the examinee can correctly identify that line.

Near vision testing: In China, the Jaeger near-vision chart and the standardized E-chart for near vision (designed by Professor Xu Guangdi) are commonly employed. The chart should be placed in well-lit conditions—ideally under daylight-mimicking fluorescent lighting. Under normal illumination, a healthy individual can clearly read line 10 at a distance of 30 cm, corresponding to a near visual acuity of 1.0. If refractive error (e.g., myopia or hyperopia) necessitates adjustment of the testing distance, this modified distance must also be documented.

We hope the above information is helpful. Wishing you a happy and healthy life!