APA Dictionary of Psychology

inability to direct saccadic eye movements (see saccade) to targets. Eye movements may either fall short of the target (undershooting: ocular hypometria) or go beyond it (overshooting: ocular hypermetria). Ocular dysmetria may be due to an oculomotor deficit (e.g., paralysis of eye muscles), poor visual localization, or impaired visuomotor coordination. Also called saccadic dysmetria.