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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 .
Pulse-width modulation supply of the machine [25] slotting effects [26] [27] [28] magnetic saturation [29] In a faulty machine, additional noise and vibrations due to electromagnetic forces can come from mechanical static and dynamic eccentricities [30] uneven air-gap [31] demagnetization; short circuits; missing magnetic wedges
An open (single envelope) CFL [12] An encapsulated/closed (double envelope) CFL. Some fluorescent lamps emit ultraviolet radiation. [citation needed] The Health Protection Agency of the United Kingdom has conducted research concluding that exposure to open (single envelope) compact fluorescent lamps (CFLs) for over 1 hour per day at a distance of less than 30 cm can exceed guideline levels as ...
Some describe seeing one or more shimmering arcs of white or colored flashing lights. An arc of light may gradually enlarge, become more obvious, and may take the form of a definite zigzag pattern, sometimes called a fortification spectrum (i.e. teichopsia , from Greek τεῖχος, town wall), because of its resemblance to the fortifications ...
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The shape properties of the light waveform (e.g. sinusoidal, rectangular pulse and its duty cycle); see Figure 1; The average light level of the light source and its contrast with the background light level within the environment; The viewing angle and changes in direction of view by the observer; Physiological factors such as age and fatigue.
A 1973 report cites a university study of fifty cases of people complaining about a "low throbbing background noise" that others were unable to hear. The sound, always peaking between 30 and 40 Hz (hertz), was found to only be heard during cool weather with a light breeze, and often early in the morning. These noises were often confined to a 10 ...
A light emitting diode (LED) incapacitator is a weapon designed like a flashlight. It emits an extremely bright, rapid, and well-focused series of "differently-colored random pulses". It emits an extremely bright, rapid, and well-focused series of "differently-colored random pulses".