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The relationship of alignment hyperacuity to stereopsis

1 May 1995


The term "alignment hyperacuity", a monocularly measured entity, is functionally described as the ability to detect an alignment of two points in space. It produces spatial thresholds usually 8 to 13 arc seconds of visual angle, which is smaller than those expected given the relatively large receptor density of the human retina. It has not been firmly established whether or not alignment hyperacuity performance is related to threshold stereopsis. This study examines the correlation between threshold stereoacuity and the sum of right and left eyes' monocular alignment detection hyperacuity measures.

Twenty-one subjects were evaluated measuring threshold stereoacuity with the Mentor BVAT II and monocular alignment hyperacuity with software designed at Pacific University College of Optometry. This study indicates that the sum of each eyes' alignment hyperacuity data should be equal to or slightly less sensitive (greater value) than an individual's threshold stereoacuity.

The lack of valid baseline knowledge about alignment detection hyperacuity and its relation to threshold stereopsis may be withholding optometric practitioners from understanding and/or testing certain aspects of alignment hyperacuity that might be of importance clinically including unexplained asthenopia, monitoring improvements in amblyopic therapy, and predicting potential stereoacuity in anti-strabismic treatment.


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