33. Saccades

Test optokinetic nystagmus (OKN) by moving a strip with parallel stripes on it in front of the patient's eyes and asking them to watch the stripes go by. Normally, rhythmic eye movements called nystagmus occur consisting of an alternating slow phase, with slow pursuit movements in the direction of strip movement, and a rapid phase, with quick, saccadic refixations back to midline. OKN testing can be very useful in detecting subtle abnormalities or asymmetries in saccadic or smooth pursuit eye movements.