Reading With the Rod Visual System

Using the scanned text technique developed by Legge and his colleagues, the present study demonstrates that visually normal subjects can read with the isolated rod visual system. The subjects were able to read text (albeit slowly) at luminances near their absolute thresholds. The peak reading rates increase with luminance at about 40 words per minute for every tenfold increase in luminance. The authors suggest that the study of scotopic reading performance in normal subjects might contribute to an understanding of reading problems in patients with bilateral central scotoma.