EFFECTS OF MAGNIFICATION ON THE HOROPTER FOR FIXATION DISTANCES OF 40CM AND 75CM

Aleksey Borodyanskiy

Abstract

PURPOSE. To systematically study the effects of monocular magnification on the 75cm and 40cm horopter. This study investigates the changes in the horopter on 10 individuals with normal binocular vision with size lenses of increasing magnification. METHOD. Subjects were asked to align test rods in an Apparent Frontoparallel Plane (AFPP) horopter device. Size lenses ranging from 0.6% to 4.9% magnification were placed over the right eye of subjects. Three trials were taken and averaged for each size lens at two fixation distances of 40cm and 75cm. To minimize effects of fatigue and learning, the trials were performed over a two-day period.

RESULTS. R0 and H values were calculated as described by Ogle (J.O.S.A. Vol 22, 1932, 538-631) for baseline data with no magnification, and for each size lens at both fixation distances. R0 values were graphed as a function of monocular magnification giving the equation y= -0.0064x +1.00 for the 40cm fixation distance data, and y= 0.0002x + 1.01 for the 75cm fixation distance data. H values were plotted against the percentage of monocular magnification for both fixation distances. For the 40cm fixation distance, the obtained equation was y= -0.0018x + 0.18, and for the 75cm fixation distance the equation was y= 0.0424x + 0.19.

CONCLUSIONS. Based on this pilot study, changes in the horopter based on monocular magnification can be predicted to some degree. Future studies would include a larger sample size and greater range of size lenses.

Details

Year: 2001

Program Number: Poster 47

Author Affiliation: University of Missouri-St. Louis

Co-Authors: Jeremy Beatty, Srinivasa Varadharajan, Vasudevan Lakshminarayanan

Co-Author Affiliation: University of Missouri-St. Louis, University of Missouri-St. Louis, University of Missouri-St. Louis

Room: Exhibit Hall C