We may have the impression that our eyes make a series of smooth movements when we read text. In reality, however, the eyes make very abrupt jumps, called Saccades, which take the gaze of the eye to the next part of the text, whist skipping out several words. During these fast abrupt movements the brain plugs in the holes, as relatively no visual material is registered. After each saccade the eyes are briefly motionless. These are called Fixations and this is when the majority of word processing arises. Throughout a fixation we distinguish letter identities, classify the relative place of each letter and activate a word in our cerebral vocabulary that best matches the visual input. What is most impressive is that all these functions happen within 200 milliseconds. A huge amount of data has shown that eye movements are often abnormal in dyslexia. Such a finding is not surprising when one considers the kinds of problems frequently observed in dyslexic readers, which include skipping letters or words, losing one’s place and difficulty with visual search activities. Eye tracking recordings allow us to literally observe a child’s eye movements, as they read a passage of text, and this provides a brilliant opportunity to study their reading development.
- Clinical Eye Tracker Software
- Eye Trace
- Testing Possible Interventions
Produced by Professor David Thomson the eye tracker software records exactly where the patient is looking whilst reading a few paragraphs of age specific text.
The horizontal and vertical position of the eyes are recorded, producing a series of saccadic eye movements and fixations.
A range of stimuli can be presented to record the eye tracking behaviour. The rate of reading test permits comparison using coloured overlays.
The video clip below demonstrates a typical eye trace when reading a passage of text.
37 Lavant Street, Petersfield, Hampshire, GU32 3EL, 01730 264258