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  2. Prism correction - Wikipedia

    en.wikipedia.org/wiki/Prism_correction

    Prism correction is measured in prism dioptres. A prescription that specifies prism correction will also specify the "base". The base is the thickest part of the lens and is opposite from the apex. Light will be bent towards the base and the image will be shifted towards the apex.

  3. Adjustable-focus eyeglasses - Wikipedia

    en.wikipedia.org/wiki/Adjustable-focus_eyeglasses

    Adjustable focus eyeglasses are eyeglasses with an adjustable focal length. They compensate for refractive errors (such as presbyopia) by providing variable focusing, allowing users to adjust them for desired distance or prescription, or both.

  4. Binoculars - Wikipedia

    en.wikipedia.org/wiki/Binoculars

    Alignment is performed by small movements to the prisms, by adjusting an internal support cell or by turning external set screws, or by adjusting the position of the objective via eccentric rings built into the objective cell.

  5. Prism (optics) - Wikipedia

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

    By shifting corrective lenses off axis, images seen through them can be displaced in the same way that a prism displaces images. Eye care professionals use prisms, as well as lenses off axis, to treat various orthoptics problems: Diplopia (double vision) Positive and negative fusion problems [ambiguous] [citation needed]

  6. Upside down goggles - Wikipedia

    en.wikipedia.org/wiki/Upside_down_goggles

    They are constructed using sets of optical right-angle prisms, concave mirrors, or a mirror plus right-angle prisms with unequal cathethus. Purpose [ edit ] Upside down goggles can be used to demonstrate human adaptation to inverted vision, and as a method of preventing motion sickness. [2]

  7. List of The Magic School Bus episodes - Wikipedia

    en.wikipedia.org/wiki/List_of_The_Magic_School...

    Ms. Frizzle and Liz have invented a magical pinball machine that uses light instead of balls. (The light travels much slower than in the real world.) It goes through a prism and the player attempts to bounce the different colored beams of light into the appropriate eye in order to "make the rainbow". Ms.

  8. 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. It is used by ophthalmologists and orthoptists in order to measure the vertical and horizontal deviation and includes both manifest and latent components. [1]

  9. Hirschberg test - Wikipedia

    en.wikipedia.org/wiki/Hirschberg_test

    In a person with normal ocular alignment the light reflex lies slightly nasal from the center of the cornea (approximately 11 prism diopters—or 0.5mm from the pupillary axis), as a result of the cornea acting as a temporally-turned convex mirror to the observer.

  10. Subjective refraction - Wikipedia

    en.wikipedia.org/wiki/Subjective_refraction

    Subjective refraction. (Top) 0.50 confirmation set; (Middle) trial lens box, including pinhole and occluder; (Bottom) Snellen chart. Subjective Refraction is a technique to determine the combination of lenses that will provide the best corrected visual acuity (BCVA). [1] It is a clinical examination used by orthoptists, optometrists and ...

  11. Herschel wedge - Wikipedia

    en.wikipedia.org/wiki/Herschel_Wedge

    A Herschel wedge or Herschel prism is an optical prism used in solar observation to refract most of the light out of the optical path, allowing safe visual observation. It was first proposed and used by astronomer John Herschel in the 1830s.