FIG. 4.

Binocular scores in healthy children using (A) ETDRS, (B) 2.5% contrast, and (C) 1.25% contrast charts. Binocular high-contrast visual acuity scores increase with age (P < 0.0001), with a linear increase in childhood until 14.4 years of age (P = 0.0002) but not in the 15 to 20-year-old participants (P = 0.69). For low-contrast visual acuity, although there was difference in scores across the age span (2.5% charts, P = 0.054; and 1.25% charts, P = 0.03), a linear trend was not found in children younger than 15 years or children older than 15 years (all P > 0.09).