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  2. Adaptation (eye) - Wikipedia

    en.wikipedia.org/wiki/Adaptation_(eye)

    Night vision is of lower quality than day vision because it is limited in resolution and colors cannot be discerned; only shades of gray are seen. [1] In order for humans to transition from day to night vision they must undergo a dark adaptation period of up to two hours [ 2 ] in which each eye adjusts from a high to a low luminescence "setting ...

  3. Night vision - Wikipedia

    en.wikipedia.org/wiki/Night_vision

    A specific type of NVD, the night vision goggle (NVG) is a night vision device with dual eyepieces. The device can utilize either one intensifier tube with the same image sent to both eyes, or a separate image intensifier tube for each eye. Night vision goggles combined with magnification lenses constitutes night vision binoculars.

  4. Nyctalopia - Wikipedia

    en.wikipedia.org/wiki/Nyctalopia

    Nyctalopia (/ ˌ n ɪ k t ə ˈ l oʊ p i ə /; from Ancient Greek νύκτ-(núkt-) ' night ' ἀλαός (alaós) ' blind, invisible ' and ὄψ (óps) ' eye '), [1] also called night blindness, is a condition making it difficult or impossible to see in relatively low light. It is a symptom of several eye diseases.

  5. Entoptic phenomenon - Wikipedia

    en.wikipedia.org/wiki/Entoptic_phenomenon

    The first two sort of floaters may collect over the fovea (the center of vision), and therefore be more visible, when a person is lying on his or her back looking upwards. Blue field entoptic phenomenon has the appearance of tiny bright dots moving rapidly along squiggly lines in the visual field.

  6. Night-vision device - Wikipedia

    en.wikipedia.org/wiki/Night-vision_device

    The effect on the natural night vision of the eye is evident A standard telescopic sight augmented with a night-vision device in front on the M110. Note that in addition to the image intensifier, the NVD gathers much more light by its much larger aperture A 1PN51-2 night-vision reticle with markings for range estimation First-person view ...

  7. Purkinje effect - Wikipedia

    en.wikipedia.org/wiki/Purkinje_effect

    An animated sequence of simulated appearances of a red flower (of a zonal geranium) and background foliage under photopic, mesopic, and scotopic conditions. The Purkinje effect or Purkinje phenomenon (Czech: [ˈpurkɪɲɛ] ⓘ; sometimes called the Purkinje shift, often pronounced / p ər ˈ k ɪ n dʒ i /) [1] is the tendency for the peak luminance sensitivity of the eye to shift toward the ...

  8. Troxler's fading - Wikipedia

    en.wikipedia.org/wiki/Troxler's_fading

    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. Research suggests that at least some portion of the perceptual phenomena ...

  9. Orthokeratology - Wikipedia

    en.wikipedia.org/wiki/Orthokeratology

    Orthokeratology lens. Orthokeratology, also referred to as Night lenses, Ortho-K, OK, Overnight Vision Correction, Corneal Refractive Therapy (CRT), Accelerated Orthokeretology, Cornea Corrective Contacts, Eccentricity Zero Molding, and Gentle Vision Shaping System (GVSS), is the use of gas-permeable contact lenses that temporarily reshape the cornea to reduce refractive errors such as myopia ...