REDUCED VERGENCE RESPONSE VELOCITIES IN READING DISABLED: A PRELIMINARY REPORT.

Two subjects were diagnosed as mildly reading disabled based on standard psycho-educational tests. Both their reading and sequential-light-tracking eye movements showed a large number of regressions. Two other normal subjects served as controls. All four subjects were tested with convergent and divergent ramp disparity stimuli ranging in speed from 1. 33 to 32. 0 deg/s and steps of 2 and 4 degrees amplitude. A 23-year-old reading disabled showed markedly reduced vergence response velocities as compared to normals while the 14-year-old reading disabled showed slight reduction in vergence velocities. These preliminary findings indicate that vergence response velocities are reduced in reading disabled subjects and suggest that the reduced vergence facility may be either a factor contributing to or a manifestation of the central deficit causing the reading disability.