Search results
Results from the WOW.Com Content Network
Abbe number. In optics and lens design, the Abbe number, also known as the V-number or constringence of a transparent material, is an approximate measure of the material's dispersion (change of refractive index versus wavelength), with high values of V indicating low dispersion. It is named after Ernst Abbe (1840–1905), the German physicist ...
The Abbe number for a material at a particular refractive index formulation is usually specified as its Abbe value. In practice, an Abbe number change from 30 to 32 will not have a practically noticeable benefit, but a change from 30 to 47 could be beneficial for users with strong prescriptions that move their eyes and look "off-axis" of the ...
Family medicine physician. Family medicine[ note 1] is a medical specialty within primary care that provides continuing and comprehensive health care for the individual and family across all ages, genders, diseases, and parts of the body. [ 2][ 3] The specialist, who is usually a primary care physician, is named a family physician. [ note 2] It ...
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. The abbreviation stands for "Columbia Resin #39", which was the 39th formula of a thermosetting plastic developed by the Columbia Resins project in 1940. [ 1]
Chromatic aberration. Focal length of lens varies with the color of light. In optics, chromatic aberration ( CA ), also called chromatic distortion, color aberration, color fringing, or purple fringing, is a failure of a lens to focus all colors to the same point. [ 1][ 2] It is caused by dispersion: the refractive index of the lens elements ...
Universal Numbering System. Universal numbering system. This is a dental practitioner view, so tooth number 1, the rear upper tooth on the patient's right, appears on the left of the chart. The Universal Numbering System, sometimes called the "American System", is a dental notation system commonly used in the United States. [ 1][ 2]
Crown glass is a type of optical glass used in lenses and other optical components. It has relatively low refractive index (≈1.52) and low dispersion (with Abbe numbers between 50 and 85). Crown glass is produced from alkali-lime silicates containing approximately 10% potassium oxide and is one of the earliest low dispersion glasses .
In an achromatic lens, two wavelengths are brought into the same focus, here red and blue. An achromatic lens or achromat is a lens that is designed to limit the effects of chromatic and spherical aberration. Achromatic lenses are corrected to bring two wavelengths (typically red and blue) into focus on the same plane.