City Pedia Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Refractive error - Wikipedia

    en.wikipedia.org/wiki/Refractive_error

    A distant object is defined as an object located beyond 6 meters (20 feet) from the eye. When an object is located close to the eye, the rays of light from this object no longer approach the eye parallel to each other. Consequently, the eye must increase its refractive power to bring those rays of light together on the retina.

  3. Visual perception - Wikipedia

    en.wikipedia.org/wiki/Visual_perception

    Visual perception is the ability to interpret the surrounding environment through photopic vision (daytime vision), color vision, scotopic vision (night vision), and mesopic vision (twilight vision), using light in the visible spectrum reflected by objects in the environment. This is different from visual acuity, which refers to how clearly a ...

  4. Photopsia - Wikipedia

    en.wikipedia.org/wiki/Photopsia

    Photopsia. This is an approximation of the zig-zag visual of a scintillating scotoma as a migraine aura. It moves and vibrates, expanding and slowly fading away over the course of about 20 minutes. Migraine with aura, which includes photopsia 39% of the time, typically lasts 10 to 20 minutes and often is followed by a headache.

  5. Radiation - Wikipedia

    en.wikipedia.org/wiki/Radiation

    In physics, radiation is the emission or transmission of energy in the form of waves or particles through space or a material medium. [ 1][ 2] This includes: electromagnetic radiation consists of photons, such as radio waves, microwaves, infrared, visible light, ultraviolet, x-rays, and gamma radiation (γ) particle radiation consists of ...

  6. Optics - Wikipedia

    en.wikipedia.org/wiki/Optics

    Optics is the branch of physics that studies the behaviour and properties of light, including its interactions with matter and the construction of instruments that use or detect it. [ 1] Optics usually describes the behaviour of visible, ultraviolet, and infrared light. Light is a type of electromagnetic radiation, and other forms of ...

  7. Cut-eye - Wikipedia

    en.wikipedia.org/wiki/Cut-eye

    Cut-eye is a visual gesture using one's eyes and face to communicate displeasure or disapproval, and in some case hostility. The gesture is usually performed by looking at someone out of the corners of one's eyes, then turning the eyes away quickly down towards the foot opposite the eye of the person the gesture is being performed at.

  8. Optics and vision - Wikipedia

    en.wikipedia.org/wiki/Optics_and_vision

    Optics and vision. Vision of humans and other organisms depends on several organs such as the lens of the eye, and any vision correcting devices, which use optics to focus the image. The eyes of many animals contains a lens that focuses the light of its surroundings onto the retina of the eye. This lens is essential to producing clear images ...

  9. Scotopic vision - Wikipedia

    en.wikipedia.org/wiki/Scotopic_vision

    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.