The literature on eccentric fixation includes numerous systems of classification devised by different workers. At the orthoptic and pleoptic centre at this hospital, we have tried to use some of these classifications, but have observed certain discrepancies which are discussed below. Some classifications are based on anatomical landmarks (Mayweg and Massie, 1958; von Noorden, 1959; Scully and N...

BACKGROUND The use of medial rectus pulley posterior fixation sutures to treat esotropia with convergence excess has limited support in the literature. We describe our results using this technique to treat patients with large near-distance disparities. METHODS We retrospectively analyzed records of patients with accommodative or partially accommodative esotropia and convergence excess 13(Δ) o...

Stereoscopic segregation in depth was studied using two superimposed frontoparallel surfaces displayed in dynamic random dot stereograms. The two patterns were positioned symmetrically in front of and behind a binocular fixation point. They were either stationary, or they could move relative to each other. Sensitivity for segregation was established by adding gaussian distributed disparity nois...

Children with developmental dyslexia show reading impairment compared to their peers, despite being matched on IQ, socio-economic background, and educational opportunities. The neurological and cognitive basis of dyslexia remains a highly debated topic. Proponents of the magnocellular theory, which postulates abnormalities in the M-stream of the visual pathway cause developmental dyslexia, clai...

THE purpose of treatment of all patients with strabismus is to reduce the angle of deviation to the smallest possible value and to develop the co-operation between the eyes to the highest possible degree. Normal binocular use of the eyes may be achieved in patients with fully accommodative squints of late onset and relatively short duration, but this is not always the case even in patients who ...

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...

Stereoacuity thresholds, measured with bar targets, rise as the absolute disparity of the bars is increased. One explanation for this rise is that, as the bars are moved away from the fixation plane, the stereo system uses coarser mechanisms to encode the bars' disparity; coarse mechanisms are insensitive to small changes in target disparity, resulting in higher thresholds. To test this explana...

Neurons in the inferior temporal (IT) cortex respond not only to the shape, color or texture of objects, but to the horizontal positional disparity of visual features in the right and left retinal images. IT neurons with similar shape selectivity cluster in columns. In this study, we examined how IT neurons are spatially arranged in the IT according to their selectivity for binocular disparity....