Transactions from the Xth International Orthoptics Congress 2004

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Near Far 70 60 50 40 30 20 10 0 Right Left Alternating 70 60 50 40 30 20 10 0 Right Left Alternating Sighting Sensory Sighting Sensory Figure 2: Responses (in %) of right eye, left eye or alternating dominance as assessed by the Sighting Test (light grey) and the Sensory Test (dark grey) for far and near. Alternating sensory dominance is particularly evident for near on the sensory test and there are a similar number of right and left dominant responses for far on the sensory test. Discussion These findings confirm those of Coren and Kaplan (2) in that there was no relationship found in laterality between the two forms of ocular dominance and thus each test can be categorised relative to the visual task required. That is, sighting dominance is indicated by a number of tasks which all require input from one eye either be excluded or ignored. Sensory dominance appears in situations where the system is trying to suppress visual confusion based upon conflicting inputs to the two eyes (2). Further investigations are necessary to compare success of monovision correction based on whether when the sensory or the sighting dominant eye is corrected for distance fixation. However it is important to note that a high percentage of subjects had no eye preference, particularly at near, according to the sensory test. These results were similar to the results found by Robboy and Erickson (3) who used the anisometropic blur suppression test to determine sensory ocular dominance. The smaller standard deviation of right eye response in the sensory dominance test at near also demonstrates a weaker sensory dominance than at distance where a larger standard deviation is present. The responses of a sighting dominance test therefore cannot predict the responses of s sensory dominance test and the two forms of ocular dominance can be considered to be two separate entities. Sighting dominance is indicated by a number of tasks which all require input from one eye either be excluded or ignored and sensory dominance occurs in situations where the system is trying to suppress visual confusion based upon conflicting inputs to the two eyes. References 1. Pearlman, A. (1897) The central visual pathways. in Moses RA, & Hart WM (Ed), Adler s Physiology of the Eye: Clinical Application. (pp583-618). St Louis: Mosby, 2. Coren, S., Kaplan, C. (1973) Patterns of ocular dominance. J Optom Arch Am Acad Optom 50, 283-292 3. Robboy, M., Cox, I., Erickson, P. (1990) Effects of sighting and sensory dominance on monovision high and low contrast visual acuity. CLAO J 16(4), 299-301 4
Does Dissociation Reduce Stereoacuity? Helen Davis a , Michelle Tewkesbury a , Jonathan Dominic a , John P Frisby b , David Buckley a a Academic Unit of Ophthalmology & Orthoptics University of Sheffield S10 2JF b Dept. of Psychology University of Sheffield, S.Yorkshire, S10 2TN, UK. Email: h.davis@sheffield.ac.uk Abstract Purpose: To ascertain if reduction in stereoacuity is caused by dissociation, defined as optical disruption of the equality of the visual stimulus to each eye. Methods: Experiment 1: 18 normal observers were tested using the Frisby Near Stereotest (FNS) in free-space and then in random order, the FNS seen through Bagolini glasses, Polaroid glasses and red & green glasses. Experiment 2: 29 normal observers were first tested for near with the FNS and for distance with the Frisby Davis Distance Stereotest (FD2) in free-space and then looking through Bagolini glasses with the striations at 180° to each other and perpendicular to each other. Re-testing with viewing through red/red, red/green & green/green goggles followed this. Results: Experiment 1: There was a significant (p
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Page 33 and 34: Results The distance and near stere
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Abstract Disruption of Binocular Vi
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Transactions from the Xth International Orthoptics Congress 2004

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