White spaces

insufficient for unambiguous word-recognition

The brain is heuristic (because that's more efficient in the long term). Unambiguity is for mindless machines.

The decreasing acuity of the parafovea (plus the fact that saccades do go way beyond the fovea) is exactly why [multi-letter] boumas exist; Kevin is probably correct that you don't need boumas in the fovea, and that's probably why they don't show up in his fovea-centric field testing.

This has the effect of enlarging the “uncrowded span” to the point where 5 to 8 letter words are fully accessible in a single fixation to parallel processing.

And evidence of even longer saccades* clearly extends that range, because absolute certainty is not the point; if the bouma is distinctive enough, and if the context is helpful enough, you can read it very deep into the parafovea. But there's no point referring to that as an "extended fovea" - just call it what it is: the parafovea delivering content.

* Exceptions are what let us see inside.

hhp