There's been a lot of discussion about readability over the past few years, on Typophile and elsewhere, much of it focused on the question of whether readability can be significantly improved at the type design level, or whether we're looking at diminishing returns with no significant gains in reading speed and comprehension ahead of us.
Today, while reading a book on animal perception and behaviour (Animals in translation by Temple Grandin), it struck me that we're going at this from the wrong end. Rather than designing new typefaces to try to gain some small improvement in readability of text, we should look at redesigning the human eye to make it much better at reading. I was prompted to this thought by the observation that, while human eyes have a concentration of cones in the round fovea at the back of the eye giving us sharp focused vision in a small circular area, many animals -- especially predators and prey in open plains -- have a horizontal concentration of cones, giving them a vertically shallow but much greater horizontal sharpness of focus. [This is why you often see e.g. sheep dogs lower their heads to observe a field of sheep: they are aligning their 'streak' of high focus sight.]
It seems to me that if human eyes were redesigned to have a similar horizontal concentration of cones instead of a round fovea, we would be able to massively extend the length of our saccadic jumps, and perhaps even read entire lines of text in a single fixation. Of course, this presumes we are dealing with horizontal text; Chinese and Mongolian readers may wish to have their new eyes fitted with vertical concentrations of cones. Actually, the ideal situation would be to have the arrangement user-adjustable, so that one could use a slider to move between a round fovea to a horizontal or vertical arrangement of cones depending on the task one was doing.
Of course, many people might object to the idea of having their eyeballs surgically altered in order to improve reading speed, even more than they object to having their writing systems cut up and rearranged. But if we do eventually reach the stage of being able to cure blindness with artificial eyes, i.e. by plugging into the visual cortex and feeding it signals, one could conceivably have a set of reading eyes, just as one now has reading glasses, which would not replace your normal eyes but be carried about and plugged in when one wants to read something.