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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.
The hallucinations are normally colorful, vivid images that occur during wakefulness, predominantly at night. [3] Lilliputian hallucinations (also called Alice in Wonderland syndrome), hallucinations in which people or animals appear smaller than they would be in real life, are common in cases of peduncular hallucinosis. [1]
Cyanopsia primarily affects the retina, the light-sensitive layer at the back of the eye, and sometimes the optic nerve, which transmits visual signals to the brain. The retina contains specialized cells called photoreceptors , which are responsible for detecting light and color.
Illusory palinopsia is often worse with high stimulus intensity and contrast ratio in a dark adapted state.Multiple types of illusory palinopsia often co-exist in a patient and occur with other diffuse, persistent illusory symptoms such as halos around objects, dysmetropsia (micropsia, macropsia, pelopsia, or teleopsia), Alice in Wonderland Syndrome, visual snow, and oscillopsia.
A phosphene is the perception of light without light actually entering the eye, for instance caused by pressure applied to the closed eyes. A phenomenon that could be entoptical if the eyelashes are considered to be part of the eye is seeing light diffracted through the eyelashes.
Typical symptoms of the disorder include halos or auras surrounding objects, trails following objects in motion, difficulty distinguishing between colors, apparent shifts in the hue of a given item, the illusion of movement in a static setting, visual snow, distortions in the dimensions of a perceived object, intensified hypnagogic and hypnopompic hallucinations, monocular double vision ...
A halo (from Ancient Greek ἅλως (hálōs) 'threshing floor, disk') [1] is an optical phenomenon produced by light (typically from the Sun or Moon) interacting with ice crystals suspended in the atmosphere. Halos can have many forms, ranging from colored or white rings to arcs and spots in the sky.
Palinopsia (Greek: palin for "again" and opsia for "seeing") is the persistent recurrence of a visual image after the stimulus has been removed. [1] Palinopsia is not a diagnosis; it is a diverse group of pathological visual symptoms with a wide variety of causes. Visual perseveration is synonymous with palinopsia. [dubious – discuss]