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  2. Base curve radius - Wikipedia

    en.wikipedia.org/wiki/Base_curve_radius

    Base curve radius (BCR) or simply base curve (BC) is the measure of an important parameter of a lens in optometry. On a spectacle lens , it is the flatter curvature of the front surface. On a contact lens it is the curvature of the back surface and is sometimes referred to as the back central optic radius ( BCOR ).

  3. Contact geometry - Wikipedia

    en.wikipedia.org/wiki/Contact_geometry

    If α is a contact form for a given contact structure, the Reeb vector field R can be defined as the unique element of the (one-dimensional) kernel of dα such that α(R) = 1. If a contact manifold arises as a constant-energy hypersurface inside a symplectic manifold, then the Reeb vector field is the restriction to the submanifold of the ...

  4. List of curves - Wikipedia

    en.wikipedia.org/wiki/List_of_curves

    Download QR code; Print/export Download as PDF; Printable version; In other projects ... (Peano curve) See also List of fractals by Hausdorff dimension.

  5. Radius of curvature (optics) - Wikipedia

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

    Radius of curvature (ROC) has specific meaning and sign convention in optical design. A spherical lens or mirror surface has a center of curvature located either along or decentered from the system local optical axis. The vertex of the lens surface is located on the local optical axis.

  6. Contact mechanics - Wikipedia

    en.wikipedia.org/wiki/Contact_mechanics

    Contact between a sphere and an elastic half-space and one-dimensional replaced model. Some contact problems can be solved with the method of dimensionality reduction (MDR). In this method, the initial three-dimensional system is replaced with a contact of a body with a linear elastic or viscoelastic foundation (see fig.).

  7. Contact (mathematics) - Wikipedia

    en.wikipedia.org/wiki/Contact_(mathematics)

    An osculating curve from a given family of curves is a curve that has the highest possible order of contact with a given curve at a given point; for instance a tangent line is an osculating curve from the family of lines, and has first-order contact with the given curve; an osculating circle is an osculating curve from the family of circles ...

  8. Base curve - Wikipedia

    en.wikipedia.org/?title=Base_curve&redirect=no

    This page was last edited on 2 December 2012, at 06:57 (UTC).; Text is available under the Creative Commons Attribution-ShareAlike 4.0 License; additional terms may apply.

  9. Rigid gas permeable lens - Wikipedia

    en.wikipedia.org/wiki/Rigid_gas_permeable_lens

    A rigid gas-permeable lens, also known as an RGP lens, GP lens, or colloquially, a hard contact lens, is a rigid contact lens made of oxygen-permeable polymers. Initially developed in the late 1970s, and through the 1980s and 1990s, they were an improvement over prior 'hard' lenses that restricted oxygen transmission to the eye.