College of Optometry Student Theses, Dissertations and Capstones

Document Type

Thesis

Degree Name

Master of Science (M.S.) in Clinical Vision Research

Copyright Statement

All rights reserved. This publication is intended for use solely by faculty, students, and staff of Nova Southeastern University. No part of this publication may be reproduced, distributed, or transmitted in any form or by any means, now known or later developed, including but not limited to photocopying, recording, or other electronic or mechanical methods, without the prior written permission of the author or the publisher.

Department

College of Optometry

First Advisor

Bin Zhang

Publication Date / Copyright Date

2017

Publisher

Nova Southeastern University

Abstract

Abstract Purpose: It is not clear as to whether sensory dominance is affected by test distance. Jiang et al previously reported that that the sensory dominant eyes may be affected by refractive error; however this study was done at a near distance only (60 cm). In this study, we investigated the effect of two different test distances (near, 60 cm vs distance, 6 meters) on the laterality of ocular dominance. Methods: Ocular sensory dominance was quantified in 60 subjects with a technique that involves the dichoptic presentation of a Mondrian noise and a Gabor patch. The threshold to detect the Gabor patch was measured in the presence of decreasing contrast in the Mondrian stimulus. Each eye was tested 50 times and thresholds from two eyes were compared with t-test. If the difference between the two eyes was significant, a subject was classified as having clear ocular sensory dominance and the eye that had lower thresholds was defined as the dominant one. If difference between the two eyes was not significant, a subject was classified as having unclear ocular sensory dominance. Ocular sensory dominance was measured at two different viewing distances, one for near at 60cm away and the other one for far at 6m away. Results: In 31 subjects (51.7 %), dominant eyes remained the same for near and distance viewing. In 15 (25.0 %) subjects, who showed clear ocular sensory dominance at distance, ocular sensory dominance became unclear at near. In 11 (18.3 %) subjects, that had unclear ocular sensory dominance at distance, showed clear ocular sensory dominance at near. In 3 (5.0 %) subjects, the laterality of the dominant eye switched between far and near distance. Conclusions: The effect of viewing distance on ocular sensory dominance is a continuous spectrum. In majority of the population, ocular sensory dominance is not affected. In 43.3 % of the population, ocular sensory dominance varies between unclear and clear status. Only in very rare cases, laterality of dominant eyes switches between near and distance.

Disciplines

Optometry

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