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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] posterior vitreous detachment. migraine aura ( ocular migraine / retinal migraine) migraine aura without headache. scintillating scotoma. retinal break or detachment.
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 ...
Floaters are from objects in pockets of liquid within the vitreous humour, the thick fluid or gel that fills the eye, [7] or between the vitreous and the retina. The vitreous humour, or vitreous body, is a jelly-like, transparent substance that fills the majority of the eye. It lies within the vitreous chamber behind the lens, and is one of the ...
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% ...
Photokeratitis or ultraviolet keratitis is a painful eye condition caused by exposure of insufficiently protected eyes to the ultraviolet (UV) rays from either natural (e.g. intense direct or reflected sunlight) or artificial (e.g. the electric arc during welding) sources. Photokeratitis is akin to a sunburn of the cornea and conjunctiva.
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.
Artist's depiction of a scintillating scotoma, exhibiting a flashing visual pattern similar to dazzle camouflage used during WWI. Scintillating scotoma is a common visual aura that was first described by 19th-century physician Hubert Airy (1838–1903). Originating from the brain, it may precede a migraine headache, but can also occur ...
Specialty. Neurology. Frequency. 1 in 4000 [1] 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).