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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 acephalgically (without headache), also known as visual migraine or migraine aura. [4]
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.
Specialty. Neurology, ophthalmology. Diplopia is the simultaneous perception of two images of a single object that may be displaced horizontally or vertically in relation to each other. [1] Also called double vision, it is a loss of visual focus under regular conditions, and is often voluntary.
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.
Will Netflix's 'Kaleidoscope' come back for a second season? Learn whether the heist drama has been renewed and what season 2 could be about.
Phosphene. An artist's representation of how some people may see phosphenes by retinal stimulation. A phosphene is the phenomenon of seeing light without light entering the eye. The word phosphene comes from the Greek words phos (light) and phainein (to show).
Entoptic phenomena (from Ancient Greek ἐντός (entós) 'within', and ὀπτικός (optikós) 'visual') are visual effects whose source is within the human eye itself. (Occasionally, these are called entopic phenomena, which is probably a typographical mistake.) In Helmholtz 's words: "Under suitable conditions light falling on the eye ...
Aura. An aura is a perceptual disturbance experienced by some with epilepsy or migraine. An epileptic aura is actually a minor seizure. [1] Epileptic and migraine auras are due to the involvement of specific areas of the brain, which are those that determine the symptoms of the aura. Therefore, if the visual area is affected, the aura will ...
Kaleidoscope. A toy kaleidoscope. A kaleidoscope ( / kəˈlaɪdəskoʊp /) is an optical instrument with two or more reflecting surfaces (or mirrors) tilted to each other at an angle, so that one or more (parts of) objects on one end of these mirrors are shown as a regular symmetrical pattern when viewed from the other end, due to repeated ...
Hazards. Dielectric heating from electromagnetic radiation can create a biological hazard. For example, touching or standing around an antenna while a high-power transmitter is in operation can cause burns. The mechanism is the same as that used in a microwave oven. [6]