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Many variations occur, but scintillating scotoma usually begins as a spot of flickering light near or in the center of the visual field, which prevents vision within the scotoma area. It typically affects both eyes, as it is not a problem specific to one eye. The affected area flickers but is not dark. It then gradually expands outward from the ...
Retinal migraine is a retinal disease often accompanied by migraine headache and typically affects only one eye. It is caused by ischaemia or vascular spasm in or behind the affected eye. The terms "retinal migraine" and "ocular migraine" are often confused with "visual migraine", which is a far-more-common symptom of vision loss, resulting ...
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
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.
Superior oblique myokymia is a neurological disorder affecting vision and was named by Hoyt and Keane in 1970. [1] It is a condition that presents as repeated, brief episodes of movement, shimmering or shaking of the vision of one eye, a feeling of the eye trembling, or vertical/tilted vision.
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. The illusion has also been described as "retinal persistence", [2] "persistence of impressions", [3] simply "persistence" and other variations.
Diagnosis. A way to demonstrate aniseikonia is to hold a near target ( e.g., a pen or a finger) approximately 6 inches directly in front of one eye. The person then closes one eye, and then the other. The person should notice that the target appears larger to the eye that it is directly in front of.
Anisometropia is caused by common refractive errors, such as astigmatism, far-sightedness, and myopia, in one eye. Anisometropia is likely the result of both genetic and environmental influences. Some studies suggest, in older adults, developing asymmetric cataracts may cause worsen anisometropia.
A phenomenon that could be entoptical if the eyelashes are considered to be part of the eye is seeing light diffracted through the eyelashes. The phenomenon appears as one or more light disks crossed by dark blurry lines (the shadows of the lashes), each having fringes of spectral colour.
Monocular vision is vision using only one eye. It is seen in two distinct categories: either a species moves its eyes independently, or a species typically uses two eyes for vision, but is unable to use one due to circumstances such as injury.