Dyslexia (impaired ability to learn)
Last reviewed: 23.04.2024
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Violation of the ability to learn can arise for many reasons, sometimes without an organic basis. However, neurological diseases, especially when combined with mild mental retardation or attention disorder, have a significant impact on the learning process. The very term "dyslexia" is intended for those conditions when the patient has a specific inability to read in the absence of neurological problems, normal intelligence and good health. Many of these patients are referred to ophthalmologists due to the erroneous opinion that the child's specificity in the structure of the organ of vision, eyeball movements or a physiology of vision is a cause of poor academic performance.
However, careful dynamic observation does not allow to detect specific visual disorders that occur in these patients no more often than in the control group of children of similar age. The connection with dyslexia was not detected in the following violations:
- strabismus, especially converging with a small deflection angle or lack of convergence;
- the relationship between the eye dominance of the right or left eye over the right or left arm;
- pathology of saccadic movements;
- pathological changes in the verdict;
- disorders of vestibulo-oculomotor communication;
- optokinetic nystagmus;
- dysfunction of the magnocellular ganglion cells of the geniculate body.
The relationship between some cases of dyslexia and neurological pathology is beyond doubt. CT, magnetic resonance imaging and autopsy data suggest that patients with dyslexia experience a change in the asymmetry of the brain structures present in the norm: for example, the right temporo-parietal and occipital regions are larger than the left one. Other pathoanatomical studies reveal disturbance of migration of neurons in the cortical layers to the left, especially around the Sylvian furrow and left temporal lobe. In some works, the focus is on neuronal ectopia and bilateral thalamus pathology. However, the data of the conducted studies do not allow to draw a conclusion about their involvement in specific disorders of the oculomotor system or pathology of the anterior part of the optic pathway. There is a quasi-medical opinion about the advisability of using the following treatment methods for dyslexia:
- special exercises for the development of eye movements;
- vestibulostabilizing treatment;
- glasses with darkened glasses;
- general physical training.
However, conducted scientific studies have not confirmed the effectiveness of these methods in the treatment of children with learning disabilities. This, of course, does not mean that the pathology of the visual system in children with dyslexia does not require adequate correction, but emphasizes the lack of a direct link between visual disorders and learning disability.
Thus, the role of the ophthalmologist is reduced to the study of visual and oculomotor systems and correction of the revealed disorders. It is also necessary to inform parents and help them understand the problem, explaining the importance of good learning and reconciling parents and children, who often can not understand the situation.
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