A visual evoked potential (VEP) component that appears in the power spectrum only during binocular fusion has recently been discovered. When both eyes are stimulated with the same checkerboard but at different pattern reversal rates, this fusional component appears at a frequency intermediate between the two stimulus frequencies. We have proposed a model to explain the appearance of this interm...

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...

The natural course of intermittent exotropia and the factors affecting its control has been unclear. We aim to report the natural course of our cohort of 117 Chinese children with intermittent exotropia and to identify baseline parameters that may have predictive value in the control deterioration of the disease. The visual acuity, spherical equivalent, compliance to orthoptic exercise, angle o...

Purpose: The aims of this study were to compare fusional vergence measurements between orthophoria, esophoria and exophoria, and to determine the strength of correlations between fusional convergence and divergence and angle of deviation. Methods and materials: A cross-sectional study was performed in children with best-corrected visual acuity of 0.0 LogMAR in either eye, compensated heterophor...

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 fi...

A patient with uncorrected antimetropia was found to attain motor fusion through blinking. Although this patient was also able to attain motor fusion through saccadic vergence and slow fusional vergence, he usually relied on blink vergence. In this patient, blink vergence was an efficient alternative to slow fusional vergence.

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...

Humans have two, frontally placed eyes and during reading oculomotor and sensory processes are needed to combine the two inputs into a unified percept of the text. Generally, slight vergence errors, i.e., fixation disparities, occur but do not cause double vision since disparate retinal inputs fall into Panum's fusional area, that is, a range of disparity wherein sensory fusion of the two retin...

Random-dot stereograms were found to be capable of producing fusional vergence amplitudes in the absence of monocular contours. These vergence amplitudes are not an artefact of monocular contours provided by the target borders or test instrument and are comparable in range to vergence amplitudes measured clinically with second degree fusion targets in an amblyoscope. We conclude that diplopia o...