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  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. [citation needed] 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. Optics and vision - Wikipedia

    en.wikipedia.org/wiki/Optics_and_vision

    Glasses (also called eyeglasses or spectacles) are frames bearing lenses worn in front of the eyes, normally for vision correction, eye protection, or for protection from UV rays. Modern glasses are typically supported by pads on the bridge of the nose and by temple arms placed over the ears .

  4. Photometry (optics) - Wikipedia

    en.wikipedia.org/wiki/Photometry_(optics)

    The eye has different responses as a function of wavelength when it is adapted to light conditions (photopic vision) and dark conditions (scotopic vision). Photometry is typically based on the eye's photopic response, and so photometric measurements may not accurately indicate the perceived brightness of sources in dim lighting conditions where ...

  5. Fresnel equations - Wikipedia

    en.wikipedia.org/wiki/Fresnel_equations

    At a dielectric interface from n 1 to n 2, there is a particular angle of incidence at which R p goes to zero and a p-polarised incident wave is purely refracted, thus all reflected light is s-polarised. This angle is known as Brewster's angle, and is around 56° for n 1 = 1 and n 2 = 1.5 (typical glass).

  6. Phase angle - Wikipedia

    en.wikipedia.org/wiki/Phase_angle

    Phase angle may refer to: Phase (waves), the angular displacement of a sinusoid from a reference point or time; Phasor angle, angular component of the complex number representation of a sinusoid; Analytic representation phase, instantaneous phase of an analytic signal representation; Phase angle (astronomy), the angle between the incident light ...

  7. Eye examination - Wikipedia

    en.wikipedia.org/wiki/Eye_examination

    An eye examination, commonly known as an eye test, [1] is a series of tests performed to assess vision and ability to focus on and discern objects. [2] It also includes other tests and examinations of the eyes. [2] Eye examinations are primarily performed by an optometrist, ophthalmologist, or an orthoptist.

  8. Waveguide (optics) - Wikipedia

    en.wikipedia.org/wiki/Waveguide_(optics)

    An optical waveguide is a physical structure that guides electromagnetic waves in the optical spectrum.Common types of optical waveguides include optical fiber waveguides, transparent dielectric waveguides made of plastic and glass, liquid light guides, and liquid waveguides.

  9. Angle of incidence (optics) - Wikipedia

    en.wikipedia.org/wiki/Angle_of_incidence_(optics)

    The angle of incidence, in geometric optics, is the angle between a ray incident on a surface and the line perpendicular (at 90 degree angle) to the surface at the point of incidence, called the normal. The ray can be formed by any waves, such as optical, acoustic, microwave, and X-ray. In the figure below, the line representing a ray makes an ...