Over the last years, several studies have suggested a possible link between dyslexia and deficits in low-level visual processing (e.g., excessive crowding). At the same time, specially designed “dyslexia-friendly” fonts appeared on the market. This class of fonts presents two main features: the particular graphic characteristics of the letterform designed to avoid confusion between similarly shaped letters, and wider inter-letter and inter-word spacing to limit crowding. The literature testing the efficacy of “dyslexia-friendly” fonts in improving reading accuracy and increasing reading speed is controversial. We evaluated the impact of letterform (with vs. without dyslexia-friendly graphic features), inter-letter spacing (standard vs. increased), and inter-word spacing (standard vs. increased) on reading accuracy and speed. Two groups of 64 children each, with and without dyslexia, read aloud 8 equivalent texts. The data collected failed to show any effect from the letterform. As regards spacing, the data showed that reading speed is impaired by an increase in inter-letter spacing not combined with an adequate increase in inter-word spacing.

在过去的几年中，多项研究表明阅读障碍与低水平视觉处理的缺陷（例如过度拥挤）之间可能存在联系。同时，专门设计的“友好型阅读障碍者”字体出现在市场上。此类字体具有两个主要特征：字母形状的特殊图形特性，旨在避免形状相似的字母之间发生混淆，以及更大的字母间和单词间间距以限制拥挤。测试“阅读障碍友好”字体在提高阅读准确性和提高阅读速度方面的功效的文献引起争议。我们评估了字母形式（有或没有阅读困难的图形特征），字母间距（标准间距与增加）和单词间距（标准间距与增加）对阅读准确性和速度的影响。两组，每组64名儿童，有或没有诵读困难，大声朗读了8篇等效的教科书。收集的数据未能显示字母形式的任何影响。关于间距，数据表明，字母间间距的增加没有与字间间距的适当增加相结合，会损害阅读速度。