Uses and limitations of eye-movement records as measures of reading performance are discussed. Research studies and findings are cited, standards for reliability and validity are given, and types of eye-movement measures are described. Research has demonstrated that eye movements are not causes but symptoms of reading proficiency; therefore, diagnosis should deal with the factors of perception, comprehension, and material assimilation. Changes in eye-movement patterns are shown by a rapid decrease in fixation and regression frequency and in pause duration during the early grades and by much less change at higher levels. Comparisons between inefficient and efficient readers show the better readers to make fewer fixations, fewer regressions, and shorter pauses and to vary their eye-movement patterns according to the kind and difficulty of materials read. The role of eye movement in oral reading, in the study of legibility of print, and in reading speed is presented. References are included. (JB)