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A scotoma may include and enlarge the normal blind spot. Even a small scotoma that happens to affect central or macular vision will produce a severe visual disability, whereas a large scotoma in the more peripheral part of a visual field may go unnoticed by the bearer because of the normal reduced optical resolution in the peripheral visual field.
Scintillating scotoma is a common visual aura that was first described by 19th-century physician Hubert Airy (1838–1903). Originating from the brain, it may precede a migraine headache , but can also occur acephalgically (without headache), also known as visual migraine or migraine aura. [ 4 ]
Distribution of rods and cones along a line passing through the fovea and the blind spot of a human eye [1]. A blind spot, scotoma, is an obscuration of the visual field.A particular blind spot known as the physiological blind spot, "blind point", or punctum caecum in medical literature, is the place in the visual field that corresponds to the lack of light-detecting photoreceptor cells on the ...
Visual field-tubular vision Visual field-central scotoma. Lesions involving the whole optic nerve cause complete blindness on the affected side, that means damage at the right optic nerve causes complete loss of vision in the right eye. [3] Optic neuritis involving external fibers of the optic nerve causes tunnel vision. [4]
During an eye examination, the presence of suppression and the size and location of the suppression scotoma may be the Worth 4 dot test (a subjective test that is considered to be the most precise suppression test), or with other subjective tests such as the Bagolini striated lens test, or with objective tests such as the 4 prism base out test.
Siedel's sickle-shaped scotoma: Paracentral scotoma joins with the blind spot to form Siedel's sickle-shaped scotoma. Arcuate or Bjerrum's scotoma : This kind of scotoma is formed at later stages of glaucoma by extension of Seidel's scotoma in an area either above or below the fixation point to reach the horizontal line.
Photopsia; This is an approximation of the zig-zag visual of a scintillating scotoma as a migraine aura. It moves and vibrates, expanding and slowly fading away over the course of about 20 minutes.
Chiasmal syndrome is the set of signs and symptoms that are associated with lesions of the optic chiasm, manifesting as various impairments of the affected's visual field according to the location of the lesion along the optic nerve.