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The correlation of Brock String Response, fixation disparity, and anticipation timing

1 May 1994


This study investigated the relationship between ocular alignment as measured by the standard distance Brock String, and by the Mentor 0&0 B-VAT II. It also studied the possible relationship between ocular alignment and the anticipation of the occurrence of a dynamic event, as measured by the Bassin Anticipation Timer. In addition to the standard lateral fixation disparity measurements taken with the B-VAT and distance Brock String, a second Brock String measurement was taken. Subjects were asked if they perceived a fused portion of the string and if so, to determine the bead's location within the fused section of string. Statistical comparisons made between distance Brock String and B-VAT fixation disparity performances did not yield the significant results neccesary to conclude that distance Brock String responses accurately represent any one fixation disparity category (eso, exo, or ortho). In addition, no statistically significant relationship was determined between distance Brock String or B-VAT fixation disparities and any of the Bassin Anticipation Timer data. 47 of 71 subjects (66%) perceived fused sections of the distance Brock String. This high frequency of occurrence indicates the need to expand the standard instruction set when utilizing the distance Brock String.


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