Brief Report  |   January 2018
Effects of Lighting on Reading Speed as a Function of Letter Size
Author Affiliations
  • William Seiple, PhD, is Vice President of Research, Lighthouse Guild, New York, NY; Research Professor, Department of Ophthalmology, New York University School of Medicine, New York; and Adjunct Faculty, Institut de la Vision, Aging in Vision and Action, Paris, France; whs4@nyu.edu
  • Olga Overbury, PhD, is Professor, School of Optometry, University of Montreal, Montreal, Quebec, Canada
  • Bruce Rosenthal, OD, is Low Vision Optometrist, Lighthouse Guild, New York, NY
  • Tiffany Arango, MA, is Research Assistant, Lighthouse Guild, New York, NY
  • J. Vernon Odom, PhD, is Professor, Department of Ophthalmology, West Virginia University Eye Institute, Morgantown
  • Alan R. Morse, PhD, is President and Chief Executive Officer, Lighthouse Guild, New York, NY
Article Information
Vision / Columns: Brief Report
Brief Report   |   January 2018
Effects of Lighting on Reading Speed as a Function of Letter Size
American Journal of Occupational Therapy, January 2018, Vol. 72, 7202345020p1-7202345020p7. doi:10.5014/ajot.2018.021873
American Journal of Occupational Therapy, January 2018, Vol. 72, 7202345020p1-7202345020p7. doi:10.5014/ajot.2018.021873
Abstract

OBJECTIVE. We sought to determine under what conditions brighter lighting improves reading performance.

METHOD. Thirteen participants with typical sight and 9 participants with age-related macular degeneration (AMD) read sentences ranging from 0.0 to 1.3 logMAR under luminance levels ranging from 3.5 to 696 cd/m2.

RESULTS. At the dimmest luminance level (3.5 cd/m2), reading speeds were slowest at the smaller letter sizes and reached an asymptote for larger sizes. When luminance was increased to 30 cd/m2, reading speed increased only for the smaller letter sizes. Additional lighting did not increase reading speeds for any letter size. Similar size-related effects of luminance were observed in participants with AMD.

CONCLUSION. In some instances, performance on acuity-limited tasks might be improved by brighter lighting. However, brighter lighting does not always improve reading; the magnitude of the effect depends on the text size and the relative changes in light level.