purpose: to compare fusional vergence amplitudes in patients with symptomatic and asymptomatic near exophoria methods: this cross-sectional study included 102 patients with near exophoria and asthenopia and 86 with asymptomatic near exophoria, all of whom were aged 15-35 years and had best corrected far visual acuity better than 20/25. far and near fusional vergence amplitudes were evaluated in...

AIM To study the prevalence of nearpoint vergence anomalies (convergence insufficiency, convergence excess and fusional vergence dysfunction) and association with gender, age groups, grade level and study site (suburban and rural). METHODS The study design was cross sectional and data was analyzed for 1201 high school students aged 13-19 years who were randomly selected from 13 high schools i...

PURPOSE Binocular alignment typically includes motor fusion compensating for heterophoria. This study evaluated heterophoria and then accommodation and vergence responses during measurement of fusional ranges in infants and preschoolers. METHODS Purkinje image eye tracking and eccentric photorefraction (MCS PowerRefractor) were used to record the eye alignment and accommodation of uncorrected...

Traditional measurements of fixation disparity, like other binocular measurements, confound influences from both blur-driven and disparity-driven components. Measuring fixation disparity with accommodation open-loop eliminates accommodative interactions, and results show fixation disparity is reduced to about half the value observed normally for high levels of forced vergence. Thus fixation dis...

We describe the challenges of resource creation for a resource-light system for morphological tagging of fusional languages (Feldman and Hana, 2010). The constraints on resources (time, expertise, and money) introduce challenges that are not present in development of morphological tools and corpora in the usual, resource intensive way.

PURPOSE : The purpose of this article is to compare vision therapy/orthoptics, pencil pushups, and placebo vision therapy/orthoptics as treatments for symptomatic convergence insufficiency in adults 19 to 30 years of age. METHODS : In a randomized, multicenter clinical trial, 46 adults 19 to 30 years of age with symptomatic convergence insufficiency were randomly assigned to receive 12 weeks ...

Convergence insufficiency (CI) is a developmental visual anomaly defined clinically by a reduced near point of convergence, a reduced capacity to view through base-out prisms (fusional convergence); coupled with asthenopic symptoms typically blur and diplopia. Experimental studies show reduced vergence parameters and tonic adaptation. Based upon current models of accommodation and vergence, we ...

PURPOSE To find out whether adaptation to a vertical prism involves more than fusional vertical eye movements. METHODS Adaptation to a vertical base-up 3 prism diopter prism was measured in a custom-programmed Maddox test in nine visually normal emmetropic subjects (mean age 27.0 ± 2.8 years). Vertical eye movements were binocularly measured in six of the subjects with a custom-programmed bin...

PURPOSE This study was designed to determine the repeatability of fusional vergence ranges measured using the rotary prisms in the phoropter and in free space using the prism bar. The level of agreement between the two methods was also investigated. METHODS In two separate sessions, negative and positive fusional vergence ranges (NFV and PFV, respectively) were measured at distance and near i...