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  2. Human eye - Wikipedia

    en.wikipedia.org/wiki/Human_eye

    The human eye is an organ of the sensory nervous system that reacts to visible light and allows the use of visual information for various purposes including seeing things, keeping balance, and maintaining circadian rhythm . Arizona Eye Model. "A" is accommodation in diopters. The eye can be considered as a living optical device.

  3. Corrective lens - Wikipedia

    en.wikipedia.org/wiki/Corrective_lens

    Corrective lens. A pair of contact lenses, positioned with the concave side facing upward. 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.

  4. List of optometric abbreviations - Wikipedia

    en.wikipedia.org/wiki/List_of_optometric...

    Esophoria: ET Esotropia: Supp. Suppression V Vision (unaided) VA Visual acuity VA Dcc - VA Dsc Visual acuity with Distant chart with correctors Visual acuity with eye chart at Distant 20 feet (6 m) and with (cc: Latin cum correctore) correctors (spectacles); Dsc is without (sc: Latin sine correctore) correctors. See Visual_acuity#Legal_definitions

  5. 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]

  6. Uppendahl prism - Wikipedia

    en.wikipedia.org/wiki/Uppendahl_prism

    An Uppendahl prism is an erecting prism, i.e. a special reflection prism that is used to invert an image (rotation by 180°). The erecting system consists of three partial prisms made of optical glass with a high refractive index cemented together to form a symmetric assembly and is [2] used in microscopy as well as in binoculars technology.

  7. Parks–Bielschowsky three-step test - Wikipedia

    en.wikipedia.org/wiki/Parks–Bielschowsky_three...

    Extraocular muscle. The Parks–Bielschowsky three-step test, [1] also known as Park's three-step test or Bielschowsky head tilt test, [2] is a method used to isolate the paretic extraocular muscle, particularly superior oblique muscle and trochlear nerve (fourth cranial nerve), [3] in acquired vertical double vision. [4]

  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. Periscope - Wikipedia

    en.wikipedia.org/wiki/Periscope

    Principle of the periscope. The periscope on the left uses mirrors whereas the right uses prisms. a Mirrors b Prisms c Observer's eye Principle of the lens periscope. The two periscopes differ in the way they erect the image. The left one uses an erecting prism whereas the right uses an erecting lens and a second image plane. a Objective lens b ...