Foveal stimuli were used to elicit fusional convergence movements of the left eye in 5 subjects icith normal binocular vision. The amplitude of fusional convergence was measured by recording eye position. The eyes were light adapted, and the stimulus to the left eye was driven at angular velocities ranging from 1/8 to 6 degrees per second. Although large individual differences were found in the...

PURPOSE To compare the results of Worth 4-dot test (WFDT) performed in dark and light, and at different distances, with fusional control in patients with intermittent exotropia (IXT). METHODS Dark and light WFDT was performed for new IXT subjects at different distances and the results were compared with level of office-based fusional control. RESULTS Fifty IXT patients including 17 male and...

Retinal blur and disparity are two different sensory signals known to cause a change in accommodative response. These inputs have differing neurological correlates that feed into a final common pathway. The purpose of this study was to investigate the dynamic properties of monocular blur driven accommodation and binocular disparity driven vergence-accommodation (VA) in human subjects. The resul...

PURPOSE The aim of this study was to investigate the changes in accommodation and binocular vision parameters during a period of 3 years and to evaluate their potential influence on the refractive changes observed over the same period of time in a population of university students in Portugal. METHODS A 3-year longitudinal study was conducted comprising 118 young adults (34 males and 84 femal...

Background Approximately one in ten students aged 6 to 16 in Ontario (Canada) school boards have an individual education plan (IEP) in place due to various learning disabilities, many of which are specific to reading difficulties. The relationship between reading (specifically objectively determined reading speed and eye movement data), refractive error, and binocular vision related clinical me...

We report the extent to which effective asymmetrical saccadic adaptation was achieved by a myopic subject, who was exposed to "long-term" adaptation as he wore anisometropic corrective spectacles for about 40 years and also the extent of "short-term" adaptation in this subject and two other subjects, who initially made conjugate saccades, when they wore newly fitted anisometropic spectacles for...

PURPOSE To compare the effectiveness of home-based (HB) computer vergence/accommodative therapy (HB-C) to HB near target push-up therapy (HB-PU) and to HB placebo treatment (HB-P) among children aged 9 to <18 years with symptomatic convergence insufficiency (CI). METHODS In this multicenter randomized clinical trial, participants were randomly assigned to computer therapy, near target push-up...

Background Clinical microscopists are at a greater risk of developing binocular vision anomalies and asthenopia.&#x0D; Objective To assess the refractive status to explore association between presence asthenopic symptoms microscopy work among clinical working medical laboratory department.&#x0D; Method This cross-sectional study involved 37 department Dhulikhel Hospital, Nepal. The was conducte...

Eye movement recordings from humans indicated that brief exposures (200 ms) to horizontal disparity steps applied to large random-dot patterns elicit horizontal vergence at short latencies (80.9 +/- 3.9 ms, mean +/- SD; n = 7). Disparity tuning curves, describing the dependence of the initial vergence responses (measured over the period 90-157 ms after the step) on the magnitude of the steps, r...

Conflicting theories exist describing how symmetrical vergence responses, the inward or outward turning of the eyes, are mediated. Classical theories describe vergence control as mediated by visual feedback. Extensive experimental evidence indicates that two distinct control components comprise the vergence response, and a recent theory supports the concept that one of these components is not v...