enow.com Web Search

  1. Ads

    related to: eyeglass lens materials st 28 south

Search results

  1. Results from the WOW.Com Content Network
  2. CR-39 - Wikipedia

    en.wikipedia.org/wiki/CR-39

    Poly (allyl diglycol carbonate) (PADC) is a plastic commonly used in the manufacture of eyeglass lenses alongside the material PMMA ( polymethyl methacrylate ). The monomer is allyl diglycol carbonate (ADC). The term CR-39 technically refers to the ADC monomer, but is more commonly used to refer to the finished plastic.

  3. Orthokeratology - Wikipedia

    en.wikipedia.org/wiki/Orthokeratology

    Orthokeratology lens. Orthokeratology, also referred to as Night lenses, Ortho-K, OK, Overnight Vision Correction, Corneal Refractive Therapy (CRT), Accelerated Orthokeretology, Cornea Corrective Contacts, Eccentricity Zero Molding, and Gentle Vision Shaping System (GVSS), is the use of gas-permeable contact lenses that temporarily reshape the cornea to reduce refractive errors such as myopia ...

  4. Glasses - Wikipedia

    en.wikipedia.org/wiki/Glasses

    Pinhole glasses are a type of corrective glasses that do not use a lens. Pinhole glasses do not actually refract the light or change focal length. Instead, they create a diffraction limited system, which has an increased depth of field, similar to using a small aperture in photography. This form of correction has many limitations that prevent ...

  5. Photochromic lens - Wikipedia

    en.wikipedia.org/wiki/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. In the absence of activating light, the lenses return to their clear state.

  6. Corrective lens - Wikipedia

    en.wikipedia.org/wiki/Corrective_lens

    Corrective lens. 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. Glasses or "spectacles" are worn on the face a short distance in front of the eye.

  7. Fresnel lens - Wikipedia

    en.wikipedia.org/wiki/Fresnel_lens

    A Fresnel lens (/ ˈ f r eɪ n ɛ l,-n əl / FRAY-nel, -⁠nəl; / ˈ f r ɛ n ɛ l,-əl / FREN-el, -⁠əl; or / f r eɪ ˈ n ɛ l / fray-NEL [1]) is a type of composite compact lens which reduces the amount of material required compared to a conventional lens by dividing the lens into a set of concentric annular sections.

  1. Ads

    related to: eyeglass lens materials st 28 south