saccaden.

1728 E. Chambers Cycl. Saccade, in the Manage, a violent Check the Cavalier gives his Horse, by drawing both the Reins very suddenly.

1876 J. Stainer & W. A. Barrett Dict. Musical Terms 383/1 Saccade, strong pressure of a violin bow against the strings, which by forcing them to a level enables the player to produce three or four notes simultaneously.

1897 New Sydenham Soc. Lexicon Saccade, the involuntary jerking movement in the act of swallowing.

1953 Jrnl. Optical Soc. Amer. 43 495/2 These [types of eye movement] include relatively large slow waves, saccades, and slow drifts of fixation.

1962 Jrnl. Optical Soc. Amer. 52 571/2 The eye does not move continuously along a line of print in reading, but executes a regular alternation of rapid jumps, called saccades, and fixational pauses.

1967 New Scientist 20 Apr. 156/1 Apart from a rapid trembling which plays a part in the mechanism of perception itself, there are two main types of eye-movement: slow ‘drifts’ away from the target image, and rapid jerks or ‘saccades’ tending to recentre it.

1971 Sci. Amer. June 35/2 Each saccade leads to a new fixation on a different point in the visual field. Typically there are two or three saccades per second.

1974 Nature 22 Mar. 308/3 Some observers can learn to suppress small saccades completely, without decreasing the accuracy of fixation or the visibility of the target.