Figure 1. Effect of word spacing with low contrast text.

Reading speed (number of correctly-read words per minute, wpm) for single- versus double-character word spacing (bottom panels) and single- versus triple-character word spacing (top panels) for text passages with single, double or triple line spacing. Results shown are for reading text with a Michelson letter contrast of 17.5%.The individual data points in each panel show the results for each participant; the diagonal line in each panel is the ‘line of no effect’.