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The psychic staring effect (sometimes called scopaesthesia) is the claimed extrasensory ability of a person to detect being stared at. The idea was first explored by psychologist Edward B. Titchener in 1898 after students in his junior classes reported being able to "feel" when somebody was looking at them, even though they could not see this ...
Troxler's fading, also called Troxler fading or the Troxler effect, is an optical illusion affecting visual perception. When one fixates on a particular point for even a short period of time, an unchanging stimulus away from the fixation point will fade away and disappear.
Itchy eyes can be harmless and caused by allergies or eye strain, but they could also be the result of a viral infection. Experts explain how to get relief. Staring At A Screen All Day Might Be ...
A number of computer and smartphone applications adjust the computer video color temperature, reducing the amount of blue light emitted by the screen, particularly at night. Dry eye is a symptom that is targeted in the therapy of CVS. The use of over-the-counter artificial-tear solutions can reduce the effects of dry eye in CVS.
The Young-Helmholtz trichromatic theory of color vision postulated that there were three types of photoreceptors in the eye, each sensitive to a particular range of visible light: short-wavelength cones, medium-wavelength cones, and long-wavelength cones. Trichromatic theory, however, cannot explain all afterimage phenomena.
Impressions of several natural phenomena and the principles of some optical toys have been attributed to persistence of vision. In 1768, Patrick D'Arcy recognised the effect in "the luminous ring that we see by turning a torch quickly, the fire wheels in the fireworks, the flattened spindle shape we see in a vibrating cord, the continuous circle we see in a cogwheel that turns with speed". [8]
Physiological illusions, such as the afterimages [9] following bright lights, or adapting stimuli of excessively longer alternating patterns (contingent perceptual aftereffect), are presumed to be the effects on the eyes or brain of excessive stimulation or interaction with contextual or competing stimuli of a specific type—brightness, color ...
Although Wells ascribes the apparent "swimming" of the planet to telescope vibration and eye fatigue, it is likely that the autokinetic effect is also being described: Looking through the telescope, one saw a circle of deep blue and the little round planet swimming in the field.