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Visual snow: dynamic, continuous, tiny dots observed across the entire visual field at any time of the day, regardless of lighting conditions, persisting for more than three months. The dots are usually black/gray on a white background and gray/white on a black background; however, they can also be transparent, white flashing, or colored.
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 left and right eye see different, seemingly random, dot patterns; a person viewing through both eyes sees a combination of both left and right visual field disturbances. While seeing the phenomenon, lightly pressing inward on the sides of the eyeballs at the lateral canthus causes the movement to stop being fluid and the dots to move only ...
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Then one should see the sixth Purkinje as a dimmer image moving in the opposite direction. The Purkinje tree is an image of the retinal blood vessels in one's own eye, first described by Purkyně in 1823. It can be seen by shining the beam of a small bright light through the pupil from the periphery of a subject's vision.
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 retinal tear may also allow fluid to leak behind the retina, causing it to detach. This will often leak blood into the vitreous, which is seen by the patient as a sudden appearance of numerous small black dots or ribbons moving across the field of vision. Sometimes a gray curtain may appear to partially block vision in one eye.
Cyanopsia is a rare visual phenomenon characterized by a blue tint to vision. Most commonly associated with cataract surgery and certain medications, such as sildenafil, cyanopsia is typically a temporary side effect rather than a standalone disease.