Insofar as I can recollect, sort of, at least if you infer what happens when the space between words or lines is too large. The gist of the issue for a dyslexic

Insofar as I can recollect, sort of, at least if you infer what happens when the space between words or lines is too large. The gist of the issue for a dyslexic reader, as I understood it anyway, is a focus problem. Picture an ellipse of sorts over the word you're trying to focus on as you read. A dyslexic person will struggle to get the ellipse on that word, and instead gobbles up part or all of the text around it (parts of the words before and after, and parts of the words above and below) - or not enough of it? - leading to fatigue and slow read speed. If memory serves me well: - By increasing the space enough, you make it simpler for a dyslexic reader to focus on each word, improving reading speed. (Anecdotally I find web typography more readable with slightly increased line height and word spacing, so methinks it's not just dyslexic readers who benefit.) - By increasing the space too much, however, you make it harder for readers (dyslexic or not) to follow the flow of text (words become disconnected, if you will, as you've experienced in the second example), and that ends up degrading the reading speed. - Every reader (dyslexic or not) has an optimal spacial arrangement. You can kind of see the effect in action by increasing the line height, kerning, and word spacing in an html document. Increase either of those three too much and the text gets harder to read. Increase one or more of them slightly above the default values and the text will be more comfortable to read.