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The bright light overwhelms the retinas of the eyes and generally gradually fades, lasting anywhere from a few seconds to a few minutes. However, if the eyes are exposed to a high enough level of light, such as a nuclear explosion, the blindness can become permanent. Flash blindness may also occur in everyday life.
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. [5] [6] The affected area flickers but is not dark. It then gradually expands outward ...
Peripheral (posterior) vitreous detachment occurs when the gel around the eye separates from the retina. This can naturally occur with age. However, if it occurs too rapidly, it can cause photopsia which manifests in flashes and floaters in the vision. Typically, the flashes and floaters go away in a few months.
One example of a pressure phosphene is demonstrated by gently pressing the side of one's eye and observing a colored ring of light on the opposite side, as detailed by Isaac Newton. [ 7 ] [ 8 ] [ 9 ] Another common phosphene is "seeing stars" from a sneeze , laughter, a heavy and deep cough, blowing of the nose , a blow on the head or low blood ...
Visual auras can be simple or complex. Simple visual symptoms can include static, flashing, or moving lights/shapes/colors caused mostly by abnormal activity in the primary visual cortex. Complex visual auras can include people, scenes, and objects which results from stimulation of the temporo-occipital junction and is lateralized to one hemifield.
Image burn-in occurs when very bright objects lie in one's field of vision, and should not be confused with closed-eye hallucinations. Visual burn-in from bright lights is visible for a few minutes after closing the eyes, or by blinking repeatedly, but the burn-in effect slowly fades away as the retina recovers, whereas the waking-consciousness ...
Flicker vertigo, sometimes called the Bucha effect, is "an imbalance in brain-cell activity caused by exposure to low-frequency flickering (or flashing) of a relatively bright light." [ 1 ] It is a disorientation -, vertigo -, and nausea -inducing effect of a strobe light flashing at 1 Hz to 20 Hz, approximately the frequency of human brainwaves .
Photosensitive epilepsy (PSE) is a form of epilepsy in which seizures are triggered by visual stimuli that form patterns in time or space, such as flashing lights, bold, regular patterns, or regular moving patterns. PSE affects approximately one in 4,000 people (5% of those with epilepsy).