Saccadic behavior during the response to pure vergence stimuli.

If two targets are carefully aligned, the required eye movement will be symmetrical with the two eyes turning equally inward or outward: a pure vergence movement. Yet almost all responses contain saccades, a rapid tandem movement of the eyes. When saccades occur, they must either be producing an error in the desired symmetrical response or correcting an error produced by an asymmetrical vergence response.

The transient component of disparity vergence maybe an indication of progressive lens acceptability.

Presbyopia, a degenerative condition, which decreases accommodation, sets in approximately at the age of forty. One approach to correct presbyopia is the use of bifocal or progressive lenses. Naturally, some people are more prone to adapt to wearing progressive lenses than others.

Dry dissection of disparity divergence eye movements using independent component analysis.

Dry dissection, a concept developed by Lawrence Stark, includes a variety of techniques designed to isolate internal neural control components by using cleverly designed stimulus or measurement protocols. As envisioned by Stark, the concept applies only to motor systems that have multiple stimulus inputs and/or response behaviors. A new application of independent component analysis (ICA) can be used to extend the dry dissection concept to identify motor components from a single, isolated response.

Dynamic assessment of disparity vergence ramps.

Previous work has shown that the disparity vergence eye movement system responds to inward (i.e., convergent) ramp stimuli with both smooth and step-like behavior depending on target velocity.

Short-term predictive changes in the dynamics of disparity vergence eye movements.

Repetitive stimulation of the disparity vergence system to large convergent step stimuli has been shown to increase the dynamics of subsequent responses to smaller step stimuli. Here we show that decreases in the dynamics of both disparity convergence and divergence eye movements can be induced using a frequently occurring small amplitude conditioning stimulus to modify responses to a larger, occasionally presented test stimulus. In one experiment, a simple conditioning stimulus consisting of repetitive 1 degrees step stimuli was used to modify the dynamic vergence response to an occasional 4 degrees step test stimulus.