Eye Like Yours

Reading is principally a linguistic experience, employing knowledge that is shared with speech. However, the nature and arrangement of the visual symbols on the page, coupled with the fact that they are perceived by eye rather than by ear, give rise to some characteristics that are specific to reading. Using language in this modality has advantages, but we're stuck with properties of the visual system that impose their own limits.

Much is known about vision as it occurs in humans and other species, from the development of the neural substrate to the perception of three-dimensional world populated by identifiable objects and individuals situated in complex, rapidly changing visual scenes. The most important information about the role of vision is reading comes from looking at the eyes themselves. Technologies that tract exactly the eyes focus and how they move became available in the last 1960s. ..... Lightweight eye trackers can be worn like a hat, collecting data about where people look and we can see what they like to look at. Knowing where people look on web pages or when they are watching TV matters greatly to content producers and television network executives.

In the 1970s, researchers in a few labs decided to use this new tool to study reading. They were gambling because it was not clear whether anything could be learned just from watching people's eyes. Most of the reading processes happens in your mind, not your pupils. Eye movement might be useful for studying the lower level seeing part of reading, perceiving the squiggles on the page, but their potential to reveal anything about the higher level thinking part-using knowledge of language and the world to understand the message that the squiggles convey -- seemed limited. ~ Page 62