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  2. Prism correction - Wikipedia

    en.wikipedia.org/wiki/Prism_correction

    Prism dioptres. Prism correction is commonly specified in prism dioptres, a unit of angular measurement that is loosely related to the dioptre. Prism dioptres are represented by the Greek symbol delta (Δ) in superscript. A prism of power 1 Δ would produce 1 unit of displacement for an object held 100 units from the prism. [2]

  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. Periscope - Wikipedia

    en.wikipedia.org/wiki/Periscope

    e Lens of the observer's eye. f Right-angled prism. g Image-erecting prism. A periscope is an instrument for observation over, around or through an object, obstacle or condition that prevents direct line-of-sight observation from an observer's current position.

  5. Corrective lens - Wikipedia

    en.wikipedia.org/wiki/Corrective_lens

    Corrective lens. A corrective lens is a transmissive optical device that is worn on the eye to improve visual perception. The most common use is to treat refractive errors: myopia, hypermetropia, astigmatism, and presbyopia. Glasses or "spectacles" are worn on the face a short distance in front of the eye.

  6. Single-lens reflex camera - Wikipedia

    en.wikipedia.org/wiki/Single-lens_reflex_camera

    A single-lens reflex camera ( SLR) is a camera that typically uses a mirror and prism system (hence "reflex" from the mirror's reflection) that permits the photographer to view through the lens and see exactly what will be captured. With twin lens reflex and rangefinder cameras, the viewed image could be significantly different from the final ...

  7. Ray tracing (graphics) - Wikipedia

    en.wikipedia.org/wiki/Ray_tracing_(graphics)

    In 3D computer graphics, ray tracing is a technique for modeling light transport for use in a wide variety of rendering algorithms for generating digital images . On a spectrum of computational cost and visual fidelity, ray tracing-based rendering techniques, such as ray casting, recursive ray tracing, distribution ray tracing, photon mapping ...

  8. Fixation disparity - Wikipedia

    en.wikipedia.org/wiki/Fixation_disparity

    Fixation disparity. Fixation disparity is a tendency of the eyes to drift in the direction of the heterophoria. While the heterophoria refers to a fusion-free vergence state, the fixation disparity refers to a small misalignment of the visual axes when both eyes are open in an observer with normal fusion and binocular vision. [1]

  9. 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.