Eye Tracking

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Tracking skills, or the ability to control the fine eye movements required to follow a line of print, are an integral part of reading. A child with a tracking problem will often lose his or her place, skip or transpose words, and struggle with reading comprehension because of the inability to move his or her eyes accurately. 

With healthy tracking skills, rather than reading across a smooth line, a child’s eyes make a series of jumps and pauses as he or she reads.  The small jumps between words or groups of words are called saccades.  The brief pause a child makes while looking at the words is called a fixation. After a fixation, a child will move his or her eyes to the next word or group of words, performing another saccade.

This meticulous coordination of jumps and pauses is controlled by one’s central and peripheral visual systems.  Central vision processes what a child sees in clear detail and defines what he or she is looking at. Peripheral, or side vision, simultaneously locates surrounding objects and lets a child know where to look (see field of vision).  These two systems are sometimes referred to as the "Where is it?" and "What is it?" systems.  In reading, central vision processes the word, while peripheral vision locates the following word and tells a child where to aim his or her eyes next.  The integration of these two systems is what allows a child to efficiently move his or her eyes along a line of print without overshooting or undershooting, or mistakenly aiming his or her eyes at lines above or below. A lack of continuous, fluid, simultaneous integration between these two systems results in difficulty with reading smoothly, keeping track of one’s place, and reading comprehension.