Title
Effect Of Vergence Adaptation On Convergence-Accommodation: Model Simulations
Abstract
Several theoretical control models depict the adaptation effects observed in the accommodation and vergence mechanisms of the human visual system. Two current quantitative models differ in their approach of defining adaptation and in identifying the effect of controller adaptation on their respective cross-links between the vergence and accommodative systems. Here, we compare the simulation results of these adaptation models with empirical data obtained from emmetropic adults when they performed sustained near task through +2D lens addition. The results of our experimental study showed an initial increase in exophoria ( a divergent open-loop vergence position) and convergence accommodation ( CA) when viewing through +2D lenses. Prolonged fixation through the near addition lenses initiated vergence adaptation, which reduced the lens-induced exophoria and resulted in a concurrent reduction of CA. Both models showed good agreement with empirical measures of vergence adaptation. However, only one model predicted the experimental time course of reduction in CA. The pattern of our empirical results seem to be best described by the adaptation model that indicates the total vergence response to be a sum of two controllers, phasic and tonic, with the output of phasic controller providing input to the cross-link interactions.
Year
DOI
Venue
2009
10.1109/TBME.2009.2025962
IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING
Keywords
Field
DocType
Adaptive control, modeling, ophthalmic lenses, visual system
Computer vision,Exophoria,Control theory,Binocular vision,Emmetropia,Vergence,Human visual system model,Computer science,Artificial intelligence,Adaptive control,Accommodation
Journal
Volume
Issue
ISSN
56
10
0018-9294
Citations 
PageRank 
References 
1
0.63
0
Authors
4