Nystagmus is characterized by involuntary, repetitive eye movements. There are two main types, each with distinct motion patterns.
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Pendular Nystagmus: In this type, the eyes move back and forth in a smooth, swinging motion, much like a pendulum. The movement is typically equal in both directions.
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Jerk Nystagmus: This is the more common type. With jerk nystagmus, the eyes drift slowly in one direction, followed by a quick, jerking movement back to the original position. This pattern repeats continuously. The direction of the "jerk" determines the direction of the nystagmus (e.g., left-beating nystagmus means the quick phase is to the left).
Therefore, nystagmus presents either as a smooth, pendulum-like motion or as a slow drift followed by a quick jerk, depending on the specific type.
