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  2. Vertex distance - Wikipedia

    en.wikipedia.org/wiki/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 the power of the lens relative to ...

  3. Aniseikonia - Wikipedia

    en.wikipedia.org/wiki/Aniseikonia

    The optical magnification properties of spectacle lenses can be adjusted by changing parameters like the base curve, vertex distance, and center thickness. Magnification size matched lenses that are used to correct aniseikonia are known as iseikonic lenses. [3] Contact lenses may also provide less difference in retinal image size. [4]

  4. Lensmeter - Wikipedia

    en.wikipedia.org/wiki/Lensmeter

    5 – Lens holder 6 – Unknown lens 7 – Standard lens 8 – Illuminated target 9 – Light source 10 – Collimator 11 – Angle adjustment lever 12 – Power drum (+20 and -20 Diopters) 13 – Prism scale knob. A lensmeter or lensometer (sometimes even known as focimeter or vertometer), [1] [2] is an optical instrument used in ophthalmology.

  5. List of optical illusions - Wikipedia

    en.wikipedia.org/wiki/List_of_optical_illusions

    The Hollow-Face illusion is an optical illusion in which the perception of a concave mask of a face appears as a normal convex face. Hybrid image: A Hybrid image is an optical illusion developed at MIT in which an image can be interpreted in one of two different ways depending on viewing distance. Illusory contours

  6. File:Thick Lens Diagram.svg - Wikipedia

    en.wikipedia.org/wiki/File:Thick_Lens_Diagram.svg

    English: Thick lens diagram. d=thickness of lens at center; e=thickness of lens at edge; r1=radius of curvature of the first surface; r2=radius of curvature of the second surface; H=primary principal plane; H′=secondary principal plane; F=front focal point; F′=back focal point; S1=vertex of the first optical surface; S2=vertex of the second ...

  7. Optical illusion - Wikipedia

    en.wikipedia.org/wiki/Optical_illusion

    Optical illusion is also used in film by the technique of forced perspective. Op art is a style of art that uses optical illusions to create an impression of movement, or hidden images and patterns. Trompe-l'œil uses realistic imagery to create the optical illusion that depicted objects exist in three dimensions.

  8. The optical illusion hidden in the 'Mona Lisa' explained - AOL

    www.aol.com/news/2015-08-22-the-optical-illusion...

    Art historians say Leonardo da Vinci hid an optical illusion in the Mona Lisa's face: she doesn't always appear to be smiling. There's question as to whether it was intentional, but new research ...

  9. Contact lens - Wikipedia

    en.wikipedia.org/wiki/Contact_lens

    Artist's impression of Leonardo's method for neutralizing the refractive power of the cornea. Leonardo da Vinci is frequently credited with introducing the idea of contact lenses in his 1508 Codex of the eye, Manual D, [9] wherein he described a method of directly altering corneal power by either submerging the head in a bowl of water or wearing a water-filled glass hemisphere over the eye.