Which of the following is the fastest eye movement between fixation points?

• A. Saccade
• B. Pursuit
• C. Vergence
• D. Accommodation

Answer: (A)

Rapid gaze shifts, known as saccades, are the fastest eye movements used to reposition the fovea from one fixation point to another. They are ballistic, meaning once started they cannot be easily altered mid-flight, and they can reach very high speeds (hundreds of degrees per second) with very short durations. This fast, jump-like movement is what lets you scan a scene quickly. In contrast, pursuit movements are smooth tracks used to follow a moving target and are slower and continuous rather than a quick jump. Vergence adjusts the eyes’ alignment to change depth (toward or away) and isn’t about moving between fixation points rapidly. Accommodation involves changing the lens shape to focus, which is a focusing mechanism rather than an eye movement. So the rapid repositioning between fixation points is accomplished by a saccade.