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In the context of this article, "faster-than-light" means the transmission of information or matter faster than c, a constant equal to the speed of light in vacuum, which is 299,792,458 m/s (by definition of the metre) [ 3] or about 186,282.397 miles per second. This is not quite the same as traveling faster than light, since:
Abundant visible light to the eyes gives health benefits through its association with the timing of melatonin synthesis, maintenance of normal and robust circadian rhythms, and reduced risk of seasonal affective disorder. [10] On the negative side, UV is a mutagen and carcinogen for skin.
Flash blindness is caused by bleaching (oversaturation) of the retinal pigment. [ 2] As the pigment returns to normal, so too does sight. In daylight the eye's pupil constricts, thus reducing the amount of light entering after a flash. At night, the dark-adapted pupil is wide open, so flash blindness has a greater effect and lasts longer.
Another quantum effect that predicts the occurrence of faster-than-light speeds is called the Hartman effect: under certain conditions the time needed for a virtual particle to tunnel through a barrier is constant, regardless of the thickness of the barrier. [50] [51] This could result in a virtual particle crossing a large gap faster than ...
The human eye can function from very dark to very bright levels of light; its sensing capabilities reach across nine orders of magnitude. This means that the brightest and the darkest light signal that the eye can sense are a factor of roughly 1,000,000,000 apart. However, in any given moment of time, the eye can only sense a contrast ratio of ...
Scotopic vision. In the study of visual perception, scotopic vision (or scotopia) is the vision of the eye under low- light conditions. [ 1] The term comes from the Greek skotos, meaning 'darkness', and -opia, meaning 'a condition of sight'. [ 2] In the human eye, cone cells are nonfunctional in low visible light.
Glare (vision) Glare from a camera flash during a Sumo fight. Glare is difficulty of seeing in the presence of bright light such as direct or reflected sunlight or artificial light such as car headlamps at night. Because of this, some cars include mirrors with automatic anti-glare functions and in buildings, blinds or louvers are often used to ...
Pupillary light reflex. Variation in the size of the pupil in bright (left) and dim (right) environments. In this case the pupil is 3 mm in diameter on the left, and 9 mm on the right. The pupillary light reflex ( PLR) or photopupillary reflex is a reflex that controls the diameter of the pupil, in response to the intensity ( luminance) of ...