Low vision rehabilitation professionals often advise patients with central vision loss to read bolder print to improve their reading abilities. But is boldface print actually effective in improving reading performance for these patients? A team of researchers made it their goal to find out. After evaluating the effects of stroke-width of text on reading speed for patients with central vision loss, they discovered that print with stroke-widths larger than the standard does not significantly improve reading speed for these patients.

The team observed 10 participants with long-standing central vision loss as they read aloud single, short sentences presented on a computer monitor, one word at a time, using rapid serial visual presentation (RSVP). They calculated reading speed based on the RSVP word exposure duration that yielded 80% of words read correctly. The text was rendered in Courier and at six boldness levels, defined as the width of the letter-strokes normalized to that of the standard Courier font: 0.27x, 0.72x, 1x, 1.48x, 1.89x and 3.04x the standard. Reading speed was measured for -0.8x and 1.4x the critical print size (the smallest print size that can be read at the maximum reading speed).

For all participants and both print sizes, the researches found that reading speeds were essentially the same for text with stroke-width boldness ranging from 0.72x to 1.89x the standard and significantly lower for the thinnest and the boldest prints. Most importantly, they note that reading speed was not higher for the bolder print than for the standard print.