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Photopsia is the presence of perceived flashes of light in the field of vision. It is most commonly associated with: [ 4] Vitreous shrinkage or liquefaction, which is the most common cause of photopsia, causes a pull in vitreoretinal attachments, irritating the retina and causing it to discharge electrical impulses.
Cosmic ray visual phenomena, or light flashes ( LF ), also known as Astronaut's Eye, are spontaneous flashes of light visually perceived by some astronauts outside the magnetosphere of the Earth, such as during the Apollo program. While LF may be the result of actual photons of visible light being sensed by the retina, [1] the LF discussed here ...
Moore's lightning streaks are lightning type streaks ( photopsia) (seen to the temporal side) due to sudden head or eye movement in the dark. They are generally caused by shock waves in the vitreous humor hitting the retina or traction on the retina from fibers in the vitreous humor. The implication is that the vitreous is softer than normal ...
Floaters drift around your field of vision and dart away when you try to look at them directly, eventually settling at the bottom of your eye and out of your sightline. Floaters appear when the ...
Retinal hemorrhage (UK English: retinal haemorrhage) is a disorder of the eye in which bleeding occurs in the retina, the light sensitive tissue, located on the back wall of the eye. [ 1] There are photoreceptor cells in the retina called rods and cones, which transduce light energy into nerve signals that can be processed by the brain to form ...
Flash blindness is an either temporary or permanent visual impairment during and following exposure of a varying length of time to a light flash of extremely high intensity, such as a nuclear explosion, flash photograph, lightning strike, or extremely bright light, i.e. a searchlight, laser pointer, landing lights or ultraviolet light. [ 1]
A posterior vitreous detachment ( PVD) is a condition of the eye in which the vitreous membrane separates from the retina. [ 1] It refers to the separation of the posterior hyaloid membrane from the retina anywhere posterior to the vitreous base (a 3–4 mm wide attachment to the ora serrata ). The condition is common for older adults; over 75% ...
Photosensitive epilepsy. 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). [ 1]