Moshe Eizenman, PhD

Head-mounted eye trackers that can record and analyze responses from the saccadic, smooth pursuit and fixation ocular control systems have been developed. The unique functional characteristics of the eye-trackers (high temporal resolution, non-contacting etc.) have resulted in the following research projects:

1. Objective perimetry: We are developing a novel perimetry system that uses eye-movement responses to peripheral stimuli to determine the differential light threshold sensitivity of the retina. This novel approach to perimetry is more accurate than standard perimetry and will allow perimetry in subjects who have difficulty maintaining steady fixation.

2. Fixation eye movements during eccentric fixation: Eye movements of normal subjects and patients with deficient smooth pursuit system are recorded and analyzed. Based on these recordings we are developing a more complete understanding of the mechanisms responsible for the stabilization of gaze during fixation.

3. VOR in patients with peripheral vestibular lesions: Eye movements and head movements in patients with peripheral vestibular lesions are measured under dynamic head-rotations. We are using these recordings to develop a more complete understanding of the plasticity and compensation mechanisms of the oculomotor system.

4. Torsion eye-movement: We are developing a novel torsion eye-movement recording system that will provide the basis for the development of non-invasive tests of the otolith system.

5. Area of Interest (AOI) displays: The principle of AOI display is to present high-detail visual information to the observer's central field of view. In cooperation with CAE Electronics Ltd. of Montreal, we have developed an eye-tracking system that controls the AOI display on CAE's fiber-optics helmet mounted simulators.

6. Scan path analysis: We are developing an image analysis system that will determine the scanning behaviour of a subject relative to objects in her/his field of view. In this project we emphasize real-time general purpose image processing algorithms that allow automated analysis of video images.

Current Visual Evoked Potentials (VEP) analysis techniques have difficulties in estimating visual thresholds (ie, visual acuity, contrast sensitivity thresholds, etc.). We have developed a VEP analysis technique that is sufficiently sensitive to reliably detect threshold VEP responses. This system is particularly useful in estimating visual performance of infants. In our main VEP project, our objective is to determine if a defect in either the binocular sensory system or its projections to oculomotor pathways is the underlying reason for the development of congenital strabismus. Over the past four years we have recorded binocular VEP responses from more than 200 babies (1-8 months) and have developed insights into the development of the feedback control loop that links the sensory and oculomotor systems.