enow.com Web Search

  1. Ad

    related to: splitting vertical prism in glasses lens definition

Search results

  1. Results from the WOW.Com Content Network
  2. Prism correction - Wikipedia

    en.wikipedia.org/wiki/Prism_correction

    Prism lenses (here unusually thick) are used for pre-operative prism adaptation. Eye care professionals use prism correction as a component of some eyeglass prescriptions.A lens which includes some amount of prism correction will displace the viewed image horizontally, vertically, or a combination of both directions.

  3. Prism cover test - Wikipedia

    en.wikipedia.org/wiki/Prism_Cover_Test

    The prism cover test ( PCT) is an objective measurement and the gold standard in measuring strabismus, i.e. ocular misalignment, or a deviation of the eye. [1] It is used by ophthalmologists and orthoptists in order to measure the vertical and horizontal deviation and includes both manifest and latent components. [1]

  4. Prism (optics) - Wikipedia

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

    Prism (optics) An optical prism is a transparent optical element with flat, polished surfaces that are designed to refract light. At least one surface must be angled — elements with two parallel surfaces are not prisms. The most familiar type of optical prism is the triangular prism, which has a triangular base and rectangular sides.

  5. Chromatic aberration - Wikipedia

    en.wikipedia.org/wiki/Chromatic_aberration

    In optics, chromatic aberration ( CA ), also called chromatic distortion and spherochromatism, is a failure of a lens to focus all colors to the same point. [1] It is caused by dispersion: the refractive index of the lens elements varies with the wavelength of light. The refractive index of most transparent materials decreases with increasing ...

  6. Eyeglass prescription - Wikipedia

    en.wikipedia.org/wiki/Eyeglass_prescription

    Eyeglass prescription. An eyeglass prescription is an order written by an eyewear prescriber, such as an optometrist, that specifies the value of all parameters the prescriber has deemed necessary to construct and/or dispense corrective lenses appropriate for a patient. If an eye examination indicates that corrective lenses are appropriate, the ...

  7. Fixation disparity - Wikipedia

    en.wikipedia.org/wiki/Fixation_disparity

    Eye glasses with an included prism power is the optical method to reduce a fixation disparity. Different procedures have been proposed to determine the required amount of prism for the individual. Based on prism-FD curves (Fig. 3b), one can find the aligning prism sP 0 that nullifies the naturally prevailing fixation disparity sFD 0. This test ...

  8. Vertex distance - Wikipedia

    en.wikipedia.org/wiki/Vertex_distance

    Vertex distance. Vertex distance. Vertex distance is the distance between the back surface of a corrective lens, i.e. glasses (spectacles) or contact lenses, and the front of the cornea. Increasing or decreasing the vertex distance changes the optical properties of the system, by moving the focal point forward or backward, effectively changing ...

  9. Interferometry - Wikipedia

    en.wikipedia.org/wiki/Interferometry

    The vertical grey line represents an unknown optical frequency. The horizontal black lines indicate the two lowest beat frequency measurements. Optical heterodyne detection is an essential technique used in high-accuracy measurements of the frequencies of optical sources, as well as in the stabilization of their frequencies.

  10. Dispersion (optics) - Wikipedia

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

    Dispersion (optics) In a dispersive prism, material dispersion (a wavelength -dependent refractive index) causes different colors to refract at different angles, splitting white light into a spectrum. In optics and in wave propagation in general, dispersion is the phenomenon in which the phase velocity of a wave depends on its frequency; [1 ...

  11. Trifocal lenses - Wikipedia

    en.wikipedia.org/wiki/Trifocal_lenses

    Trifocal lenses are made in similar styles to bifocals, but with an additional segment for intermediate vision above the reading section. A common style is the 7×28 flat-top or D-shaped segment, 28 mm wide, with a 7 mm high intermediate segment. Larger intermediate segments are available, and are particularly useful for people who spend a lot ...