This use of the term was introduced by George Landow, and was based on Roland Barthes' use of lexia in S/Z to refer "units of reading".
[1] These are not necessarily present in the text before it is read, and can be "arbitrary, but useful" in analysis.
George Landow, writing in 1992, was one of the first scholars to analyse literary hypertexts.
Landow defined hypertext thus: "Hypertext, as the term will be used in the following pages, denotes text composed of blocks of text — what Barthes terms a lexia — and the electronic links that join them.
"[2] Scholars have noted that Landow actually uses the term lexia quite differently from Barthes.