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This study investigated the actual logMAR and contrast sensitivity demands in a cross-sectional sample of kindergarten through grade 12 classrooms in New York city. This was done to consider the potential benefit in optimising the specificity of visual acuity-based screening in school to reflect their actual needs in the classroom. The authors assessed 14 classrooms in five schools (two public and three private). In most, text was projected onto smartboards. The results show the smallest, largest, range and mean logMAR and Snellen equivalent of the letters used, and considered seat location in class. The mean visual acuity of lowercase letters was 0.93 in the centre front seat location to 0.46 centre back, 0.71 side front and 0.43 side back. Thus, visual acuity demand at the back was, on average, almost triple that of the front row. Optotypes averaged 0.79 centre front at kindergarten to 3rd grade, 0.91 for 5-7th grade and 1.02 for 9-12th grade. For evaluation of contrast, this was high for black on white at 0.00, but varied from 0.15 to 0.60 on smart boards. Thus, contrast is important in this regard. The authors discuss that children with visual acuity of 20/30 or worse may have difficulty at the back of some classrooms. Children at the front may only struggle with visual acuities below 20/80. This is useful data to support better positioning of children in classrooms who have reduced visual acuity levels.


Actual visual acuity demands in the classroom.
Adams C, Leach S, Kresch YS, Brooks SE.
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Fiona Rowe (Prof)

Institute of Population Health, University of Liverpool, UK.

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