The effect of induced blur on the Beery-Buktenica developmental test of visual-motor integration and its supplemental tests

BACKGROUND: The Beery-Buktenica Test of Visual-Motor Integration (Beery VMI) is a commonly used standardized test of visual-motor integration. Performance on the test is related to academic achievement, but the effect of reduced visual acuity on test results is unknown. This study determined the visual acuity demand and the spacing of the test forms for the Beery VMI and its supplemental tests and investigated the effect of induced optical blur on test results in both adults and children. METHODS: The overall size and critical detail size of each form and the distance between the center of each form and its adjacent crowding source were measured. The visual acuity demand and angular separation of forms were calculated. Two groups of participants (adults aged ≥18 years [n = 19] and children aged 7–12 years [n = 20]) completed four sessions in which they performed the Beery VMI and the supplemental tests under different blur conditions (habitual near correction, monocular spherical blur, binocular spherical blur and binocular astigmatic blur) in a randomized order. RESULTS: Stroke width, overall form size and box size remained constant throughout the Beery VMI, whereas these reduced with increasing difficulty for the supplemental tests. Reduced near visual acuity from simulated blur resulted in reduced mean scores for the Beery VMI and its supplemental tests, compared with habitual near vision in both adults and children. Binocular spherical blur had the most detrimental effect (p<0.001), followed by binocular astigmatic blur (p<0.001) then monocular spherical blur (p = 0.022). CONCLUSIONS: In individuals with uncorrected spherical or astigmatic ametropia, reduced scores on the Beery VMI and its supplemental tests may be due to impaired near visual acuity and not reflect reduced visual-motor abilities. This highlights the importance of excluding reduced near visual acuity as a cause of reduced performance before diagnosing impairment and initiating treatment strategies for visual-motor integration.