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  2. Health threat from cosmic rays - Wikipedia

    en.wikipedia.org/wiki/Health_threat_from_cosmic_rays

    Health threats from cosmic rays are the dangers posed by cosmic rays to astronauts on interplanetary missions or any missions that venture through the Van-Allen Belts or outside the Earth's magnetosphere. [ 1][ 2] They are one of the greatest barriers standing in the way of plans for interplanetary travel by crewed spacecraft, [ 3][ 4][ 5] but ...

  3. Flicker fusion threshold - Wikipedia

    en.wikipedia.org/wiki/Flicker_fusion_threshold

    The flicker fusion threshold, also known as critical flicker frequency or flicker fusion rate, is the frequency at which a flickering light appears steady to the average human observer. It is a concept studied in vision science, more specifically in the psychophysics of visual perception. A traditional term for "flicker fusion" is "persistence ...

  4. Electromagnetic radiation and health - Wikipedia

    en.wikipedia.org/wiki/Electromagnetic_radiation...

    Infrared wavelengths longer than 750 nm can produce changes in the lens of the eye. Glassblower's cataract is an example of a heat injury that damages the anterior lens capsule among unprotected glass and iron workers. Cataract-like changes can occur in workers who observe glowing masses of glass or iron without protective eyewear for prolonged ...

  5. Laser safety - Wikipedia

    en.wikipedia.org/wiki/Laser_safety

    Laser safety. Laser radiation safety is the safe design, use and implementation of lasers to minimize the risk of laser accidents, especially those involving eye injuries. Since even relatively small amounts of laser light can lead to permanent eye injuries, the sale and usage of lasers is typically subject to government regulations.

  6. Photosensitivity in humans - Wikipedia

    en.wikipedia.org/wiki/Photosensitivity_in_humans

    Photosensitivity in humans. Light sensitivity or photosensitivity refers to a notable or increased reactivity to light. Apart from vision, human beings have many physiological and psychological responses to light. In rare individuals an atypical response may result in serious discomfort, disease, or injury. Some drugs have a photosensitizing ...

  7. Highway hypnosis - Wikipedia

    en.wikipedia.org/wiki/Highway_hypnosis

    Highway hypnosis, also known as white line fever, is an altered mental state in which an automobile driver can safely drive lengthy distances with no recollection of consciously having done so. [ 1] In this state, the driver's conscious mind is fully focused elsewhere, while seemingly still processing the information needed to drive safely.

  8. Speed of light - Wikipedia

    en.wikipedia.org/wiki/Speed_of_Light

    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 ...

  9. Health effects of sunlight exposure - Wikipedia

    en.wikipedia.org/wiki/Health_effects_of_sunlight...

    Short-term over-exposure can cause snow blindness, which is analogous to sunburn of the cornea, or can cause solar retinopathy, which is long-lasting retinal damage and vision impairment from sungazing. [52] [53] Frequent exposure to the sun can cause yellow non-cancerous bumps on the middle part of the sclera of the eye, called pingueculae. It ...