The assumption behind eye tracking is that the longer the eye gaze fixation on a certain word is, the more difficult it is for cognitive processing (Just et al., 1996).
until now, eye tracking has not been used to investigate reading in autism, possibly due to the number of procedural difficulties related to this kind of research with autistic participants (Section 3), and thus there is no reliable information about the particular types of phrases which need simplification for readers with autism.