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  2. Corrective lens - Wikipedia

    en.wikipedia.org/wiki/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.

  3. Lens - Wikipedia

    en.wikipedia.org/wiki/Lens

    A lens is a transmissive optical device that focuses or disperses a light beam by means of refraction. A simple lens consists of a single piece of transparent material, while a compound lens consists of several simple lenses ( elements ), usually arranged along a common axis.

  4. Glasses - Wikipedia

    en.wikipedia.org/wiki/Glasses

    Glasses, also known as eyeglasses and spectacles, are vision eyewear with clear or tinted lenses mounted in a frame that holds them in front of a person's eyes, typically utilizing a bridge over the nose and hinged arms, known as temples or temple pieces, that rest over the ears.

  5. Progressive lens - Wikipedia

    en.wikipedia.org/wiki/Progressive_lens

    Progressive lenses are corrective lenses used in eyeglasses to correct presbyopia and other disorders of accommodation. They are characterised by a gradient of increasing lens power , added to the wearer's correction for the other refractive errors .

  6. Aspheric lens - Wikipedia

    en.wikipedia.org/wiki/Aspheric_lens

    Aspheric lenses are also sometimes used for eyeglasses. Aspheric eyeglass lenses allow for crisper vision than standard "best form" lenses, mostly when looking in other directions than the lens optical center.

  7. Eyeglass prescription - Wikipedia

    en.wikipedia.org/wiki/Eyeglass_prescription

    An eyeglass prescription is an order written by an eyewear prescriber, such as an optometrist, that specifies the value of all parameters the prescriber has deemed necessary to construct and/or dispense corrective lenses appropriate for a patient. If an eye examination indicates that corrective lenses are appropriate, the prescriber generally ...

  8. Bifocals - Wikipedia

    en.wikipedia.org/wiki/Bifocals

    Bifocals with separate lenses. In this case, the Swedish ethnologist Jan-Ă–jvind Swahn [ sv]. Bifocals are eyeglasses with two distinct optical powers. Bifocals are commonly prescribed to people with presbyopia who also require a correction for myopia, hyperopia, and/or astigmatism .

  9. Rimless eyeglasses - Wikipedia

    en.wikipedia.org/wiki/Rimless_eyeglasses

    Rimless eyeglasses are a type of eyeglasses in which the lenses are mounted directly to the bridge or temples. The style is divided into two subtypes: three-piece glasses are composed of lenses mounted to a bridge and two separate temple arms, while rimways (also called cortlands ) feature a supporting arch that connects the temples to the ...

  10. Toric lens - Wikipedia

    en.wikipedia.org/wiki/Toric_lens

    A toric lens is a lens with different optical power and focal length in two orientations perpendicular to each other. One of the lens surfaces is shaped like a "cap" from a torus (see figure at right), and the other one is usually spherical. Such a lens behaves like a combination of a spherical lens and a cylindrical lens.

  11. Photochromic lens - Wikipedia

    en.wikipedia.org/wiki/Photochromic_lens

    Photochromic lens. A photochromic eyeglass lens, part of the lens darkened after exposure to sunlight while the other part remained covered. A photochromic lens is an optical lens that darkens on exposure to light of sufficiently high frequency, most commonly ultraviolet (UV) radiation.