In a 2008 study, researchers Powers, Grisham, and Riles used the Developmental Eye Movement Test to measure the saccadic tracking skills of 684 ninth-grade students identified as having poor reading abilities.
Horizontal (saccadic) times were typical of grade 3 students; the average number of errors on the horizontal test was typical of grade 2 students. Both genders performed similarly. Retests showed slightly improved horizontal times and fewer errors, yet the grade-level equivalents remained dramatically low. Fewer than 10% of the students scored above the 50th percentile for eighth grade, suggesting that poor readers in high school might be at high risk for poor saccadic tracking.
Volume 79, Issue 5 , Pages 228-234, May 2008 American Optometric Association. Published by Elsevier Inc. All rights reserved.