منابع مشابه
Update on Spectacle Lens
Majority of the advances in spectacle lens continue to occur in the area of progressive lens design by most of the spectacle lens manufacturers. Since the introduction of progressive addition lenses (PALs) in 1959 by Essilor, it has gained worldwide acceptance for the treatment of presbyopia. While progressive lens design, manufacturing and dispensing techniques have grown at a good pace in the...
متن کاملPrescribing of Spectacle Lenses.
SIRS,-The attention of the Council of British Ophthalmologists has been drawn to the difficulty which the Services and the Ministry of Health are experiencing in obtaining spectacle lenses to supply their urgent needs, and it has been suggested that the situation could be helped by a simplification of the prescriptions supplied by civilian ophthalmic surgeons. LThe Council has considered the qu...
متن کاملAxial Performance of Spectacle Lenses
The measured values of the axial meridional powers for 311 spectacle lenses are reported. The spherical refractive powers range from + 7 . 0 0 to —20.00 diopters with cylindrical powers of 0.00, 1.00, and 2.00 diopters. The departures of the measured from the nominal values are shown. The probable errors of measurement are discussed. A set of tolerance values is suggested and the degree of comp...
متن کاملOn pm$^+$ and finite character bi-amalgamation
Let $f:Arightarrow B$ and $g:A rightarrow C$ be two ring homomorphisms and let $J$ and $J^{'}$ be two ideals of $B$ and $C$, respectively, such that $f^{-1}(J)=g^{-1}(J^{'})$. The bi-amalgamation of $A$ with $(B,C)$ along $(J,J^{'})$ with respect of $(f,g)$ is the subring of $Btimes C$ given by $Abowtie^{f,g}(J,J^{'})={(f(a)+j,g(a)+j^{'})/ a in A, (j,j^{'}) in Jtimes J^{'}}.$ In ...
متن کاملCharacter Processing Based on Character Ontology
We use characters as a basis for data representation in computers, and as a tool for communication over computer networks. Computer programs are made of characters, we exchange mails that are sequences of characters, and many of the contents available over the Internet are realized in the form of characters. Currently, in the field of information processing, characters are defined and shared us...
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ژورنال
عنوان ژورنال: Poetics Today
سال: 1986
ISSN: 0333-5372
DOI: 10.2307/1772760