Normative pediatric data for three tests of functional vision

To provide the normative pediatric data for three tests of functional vision.

Prospective, cross-sectional study.

The participants were 281 children between 3 and 5 years of age (mean 4.2 ± 0.8 years) participating in a preschool vision screening study.

Participants completed monocular testing with the Precision Vision Visual Acuity Testing (PVVAT) system, a computerized test of visual acuity. Stereoacuity was assessed using the Pass Test 3 Stereo Test. Noncycloplegic refractive error was measured using the Plusoptix S09 Vision Screener (PS09). The mean and 95% tolerance limits were determined for each test.

Visual acuity improved significantly from 0.31 logMAR at 3 years to 0.18 logMAR at 5 years (p < 2.4 × 10^-15). Stereoacuity improved from 104 arcsec at 3 years to 81 arcsec at 5 years (p = 0.0058). Spherical refractive error remained relatively stable at 0.29 D at 3 years and 0.24 D at 5 years (p = 0.543). Cylindrical refractive error was also relatively stable, measuring 0.39 D at 3 years and 0.31 D at 5 years (p = 0.109).

Both visual acuity and stereoacuity improved significantly from 3 to 5 years of age. Note, however, that the norms obtained using the PVVAT system were somewhat lower than those reported in previous studies using other tests. The norms for the PS09 were stable and showed relatively good agreement with the manufacturer-suggested referral criteria.