ias examination zones retinal disparity essay template for ..
In addition to interplay between the convergence and divergence mechanisms, refractive errors may further modify the innervational pattern that influences the position of the eyes. In a patient with uncorrected myopia, less than normal accommodative effort is required during near vision thus causing decreased accommodative convergence. According to Donders this constant under stimulation of convergence may cause an exodeviation to develop 15. Similarly in patients with high degree of uncorrected hypermetropia no effort is made to overcome the refractive error by an accommodative effort and clear vision is unattainable 16. This may lead to development of an exodeviation on the basis of an under stimulated and thus under active convergence mechanism that causes the AC/A ratio to remain low. Thus refractive errors through their effect on accommodation are undoubtedly one of the prime causes of misalignment of the eyes. Jampolsky et al emphasized that anisomyopia and anisoastigmatism bear distinct relationships to exodeviation 17. Unequal clarity of retinal images may present an obstacle to fusion, facilitate suppression and therefore contribute to the pathogenesis of exotropia.
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Retinal disparity 3-d essay. Term paper Academic Writing Ser
It is the ability to align the eyes in such a manner that sensory fusion can be maintained. The stimulus for these fusional eye movements is retinal disparity outside panum’s area and the eyes moving in opposite direction (vergence). Unlike sensory fusion, motor fusion is the exclusive function of the extrafoveal retinal periphery.
Microsaccades: Small steps on a long way - ScienceDirect
The simultaneous stimulation of non-corresponding or disparate retinal elements by an object point causes this point to be localized in two different subjective visual directions. An object point seen simultaneously in two directions appears double. Double vision is the hallmark of retinal disparity.