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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]
Closed-eye hallucinations and closed-eye visualizations ( CEV) are hallucinations that occur when one's eyes are closed or when one is in a darkened room. They should not be confused with phosphenes, perceived light and shapes when pressure is applied to the eye's retina, or some other non-visual external cause stimulates the eye.
Persistence of vision is the optical illusion that occurs when the visual perception of an object does not cease for some time after the rays of light proceeding from it have ceased to enter the eye. [1] The illusion has also been described as "retinal persistence", [2] "persistence of impressions", [3] simply "persistence" and other variations.
Tunnel vision; Scotoma. Blind or dark spots; Curtain like effect over one eye; Slowly spreading spots; Kaleidoscope effects; Temporary blindness in one or both eyes; Heightened sensitivity to light; Auditory changes. Hearing voices or sounds that do not exist: auditory hallucinations
Kaleidoscope. A toy kaleidoscope. A kaleidoscope ( / kəˈlaɪdəskoʊp /) is an optical instrument with two or more reflecting surfaces (or mirrors) tilted to each other at an angle, so that one or more (parts of) objects on one end of these mirrors are shown as a regular symmetrical pattern when viewed from the other end, due to repeated ...
Causes of metamorphopsia. Metamorphopsia can be a symptom of a number of eye disorders involving the retina or macula. Some of these conditions include the following: Age-related macular degeneration; Epiretinal membrane and vitreomacular traction; Posterior vitreous detachment; Macular hole; Diagnosis
Lesions in optic nerve causes visual field defects and blindness. Causes. Causes of optic nerve lesions include optic atrophy, optic neuropathy, head injury, traumatic avulsion, acute optic neuritis etc. Signs and symptoms Visual field-tubular vision Visual field-central scotoma
Neurology, ophthalmology. Diplopia is the simultaneous perception of two images of a single object that may be displaced horizontally or vertically in relation to each other. [1] Also called double vision, it is a loss of visual focus under regular conditions, and is often voluntary.
There are many causes for this condition. It may occur when the axial length of eyeball is too short or if the lens or cornea is flatter than normal. Changes in refractive index of lens, alterations in position of the lens or absence of lens are the other main causes.
Causes Peripheral (Posterior) vitreous detachment, retinal detachment, age-related macular degeneration, ocular (retinal) migraine / migraine aura, vertebrobasilar insufficiency, optic neuritis, occipital lobe infarction (similar to occipital stroke), sensory deprivation (ophthalmopathic hallucinations)