How Binocular Visual Performance Is Changed When One Eye Has Lower Vision: Characterization Of Inhibitory Binocular Interactions

Abstract

Purpose: To explore new methodologies to quantify binocular interactions and shed light on their possible neural generators. Methods: Binocular inhibition (BI) was experimentally produced in 40 visually healthy subjects by inserting a series of neutral density (ND) filters in front of one eye. Visual evoked potentials were recorded with stimuli tuned for check size, location and contrast. The Pulfrich effect was investigated using computerized pendulums. Results: Stimulus parameters required to generate maximal BI differ from those for maximal binocular summation (BS). The phase shift required to reverse the Pulfrich effect was proportional to the strength of the ND filter used, and the implicit time measured with VEPs and calculated with the PE correlate. Conclusion: It appears separate neural generators are responsible for BI and BS.