Actual Visual Acuity Demands In The Classroom

Purpose: To address the knowledge gap regarding the actual acuity requirements needed in typical kindergarten through grade 12 classrooms by determining an actual logarithm of the minimum angle of resolution (logMAR) and contrast sensitivity requirements in a sample of classrooms for kindergarten through grade 12 in New York City.Methods: Measurements of classroom dimensions with specific attention to viewing distances were made in public and private school classrooms, at various grade levels from kindergarten through grade 12, in New York City. The dimensions of typical text shown to students on classroom smartboards and whiteboards was measured and the mean and range of logMAR values were calculated for various seating locations within the classrooms. Contrast between text and background was estimated by comparing digital images of actual classroom text to Pelli-Robson contrast sensitivity charts.Results: Fourteen classrooms in five schools were evaluated. Classroom dimensions varied from 8 x 10 feet to 23 x 23 feet. Mean logMAR values of lower case text on smartboards and whiteboards varied from 0.93 +/- 0.29 (range: 0.83 to 1.32) in the center of the front row to 0.46 +/- 0.21 (range: 0.10 to 0.79) in the center of the back row (P < .001). Contrast was also variable, being highest for black markers on whiteboards (0.00) and lowest on smartboards (0.15 to 0.60). Neither logMAR nor contrast sensitivity values varied significantly by grade level or school (P > .50 for both).Conclusions: The data reveal that logMAR demands and contrast vary substantially from classroom to classroom and within a classroom based on room dimensions and seating. Although generally supporting current acuity-based pediatric vision screening referral guidelines, the data also provide insight into the potential impact of reduced visual acuity and seating location on visual performance in the classroom. These findings suggest the need to develop logMAR and contrast standards that optimize visual content in classrooms while accommodating a wider range of visual capabilities.