The Effect Of Fixation DisparityOn Binocular Visual Acuity

Abstract

Abstract This project is carried out in binocular visual acuity in the presence of fixation disparity created by prisms A sample of 20 young adults was surveyed in clinics of Faculty of Optometry and Visual Science and they had good binocular vision, reduction in binocular visual acuity with the magnitude of fixation disparity was found, to achieve our original goals a clinical investigation was carried out in normal subject with good vision (6/5) symptoms free. By using loose prisms (3-5-7-9-11). The induced misalignment of the visual axis is present and it varied from one patient to another, the vision decreased due to displaced retinal image, and there was a direct relationship between prism dioptre and fixation disparity, and an indirect relation between visual acuity and the induced fixation disparity. The subjects were selected randomly including both males and females. The age variation ranged between (21-25) years. The criteria for selection included normal binocular single vision, symptoms free. Data gathered were tabulated and calculation included frequency percentage means- standard deviation and T-test were significant, the result of induced phenomenon comparing with Log-Mar (Test vision) and the displacement of retinal image by mms, were explain the indirect relation between binocular visual acuity to the induce fixation disparity. The key words were fixation disparity and visual acuity.