3. Pursuits - Eye Movements & Binocular Vision Summer 2026

-Gaze-shifting eye movements

-Slow, conjugate tracking eye movement in response to a moving stimulus

What is a pursuit?

target velocity

What is the primary stimulus for a pursuit?

-Match the eye velocity with the target velocity

-Stabilize the object of interest on the retina

-To create a constant oculocentric direction (β)

What is the goal of a pursuit?

non-zero rate of change of β

A ______ is our stimulus to generate or adjust a pursuit eye movement

to adjust eye velocity (rate of change of ocular direction -- α) so that β is constant

What is the goal of a pursuit?

100 +/- 5msec

What is the latency period for a pursuit?

target velocity up to 60-70º/sec

Pursuit velocity will closely match what?

slower

Above 60-70º/sec, pursuits are usually (slower/faster) than target velocity

100-150

Pursuits can keep up with targets moving up to _______º/sec in some instances

horizontal; vertical

(Vertical/horizontal) pursuits are more accurate than (Vertical/horizontal) pursuits

catch up saccade

If eyes are BEHIND the target, this may trigger a saccadic eye movement called a ________

Catch-Up Saccade Diagram (Pic)

Catch-Up Saccade Diagram (Pic)

Catch-Up Saccade Diagram (Pic)

Catch-Up Saccade Diagram (Pic)

Catch-Up Saccade Diagram (Pic)

Catch-Up Saccade Diagram (Pic)

decreases

Performance of pursuits (increases/decreases) with age

error correcting or catch up saccades

What increases as we age?

educated guesses

Knowledge of the target allows _______ as to its future behavior

patients can track objects more accurately

What happens to pursuits when patients can make educated guesses about future target behavior?

2 plots (just like for VOR)

What does the Bode Analysis for Pursuits contain?

-Gain vs frequency

-Phase vs Frequency

What are the 2 Bode plots that describe Pursuits?

0º

What is the ideal phase of pursuits?

Bode Plots (Pic)

Bode Plots (Pic)

Several studies show that is it possible to train pursuits. After 7.5 min subjects learned to track an odd target movement. Included 3 Pirate baseball platers who had much lower initial tracking errors than other subjects; however after training, all subjects plateau at some final error score

Are we able to train pursuits?

Barbiturates can eliminate smooth pursuits but leave saccadic intact. To follow a target, patients have to make a series of saccadic movements

How do drugs affect pursuits?

10 ft

You can only pursue a baseball until about ______

pursuits -- in an attempt to stabilize the retinal image and thus provide better resolution

When measuring VA with a moving target, what eye movement is utilized?