The role of accommodative convergence at the limits of fusional vergence.
نویسندگان
چکیده
Two possible explanations are presented for the mechanism which limits the maximum fusional vergence response. An experimental paradigm is developed to differentiate between these alternatives. Experimental results indicate that the blur generally associated with strong fusional effort is due to convergence accommodation "overdrive." Th important theoretical and clinical implications of this finding are presented.
منابع مشابه
Evaluation of ocular accommodation, convergence and fusional vergence changes during Ramadan
Purpose: There are a few researches regarding the effects of Islamic fasting on visual system. The aim of this study was to investigate the effects of Ramadan fasting on the amplitude of accommodation (AA), near point of convergence (NPC), positive and negative fusional vergences (PFV and NFV, respectively) in visually healthy fasters. Methods: AA, NPC, PFV and NFV at far (6m) and near (40cm) w...
متن کاملRandomized clinical trial of treatments for symptomatic convergence insufficiency in children.
OBJECTIVE To compare home-based pencil push-ups (HBPP), home-based computer vergence/accommodative therapy and pencil push-ups (HBCVAT+), office-based vergence/accommodative therapy with home reinforcement (OBVAT), and office-based placebo therapy with home reinforcement (OBPT) as treatments for symptomatic convergence insufficiency. METHODS In a randomized clinical trial, 221 children aged 9...
متن کاملNatural strabismus in monkeys: accommodative errors assessed by photorefraction and their relationship to convergence errors.
PURPOSE To examine accommodation and accommodative convergence relationships in naturally strabismic monkeys. METHODS Photorefraction was used to measure accommodative responses of each eye under monocular and binocular viewing conditions. These accommodative results were then compared to assessments of vergence state made under monocular viewing conditions using methods previously described....
متن کاملA review of convergence insufficiency: what are we really accomplishing with exercises?
INTRODUCTION Orthoptic exercises have been the primary treatment for convergence insufficiency since this condition's first description in 1855. It is presumed that exercises work by improving fusional convergence. In recent years, research from eye movement laboratories has challenged our theories on the nature and dynamics of convergence, the effect of convergence exercises, and the etiology ...
متن کاملVergence anomalies in a sample of high school students in South Africa
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...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Investigative ophthalmology & visual science
دوره 18 9 شماره
صفحات -
تاریخ انتشار 1979