Premium
A method of determining the equivalent powers of the eye and its crystalline lens without resort to phakometry
Author(s) -
Beenett A.G.
Publication year - 1988
Publication title -
ophthalmic and physiological optics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.147
H-Index - 66
eISSN - 1475-1313
pISSN - 0275-5408
DOI - 10.1111/j.1475-1313.1988.tb01082.x
Subject(s) - keratometer , lens (geology) , norm (philosophy) , optics , principal (computer security) , refractive error , directional derivative , mathematics , physics , computer science , optometry , mathematical analysis , cornea , medicine , visual acuity , law , operating system , political science
If the positions of the principal points of the crystalline lens are conjectured, its equivalent power and that of the eye can be calculated as described from ocular dioptrics. The only data required are the subject's refractive error and the results of keratometry adn A‐scan ultrasonography. The method assumes the profile of the lens of conform to and arbitrary norm. If the unkown lesn profile of given eye differs from this norm, errors will arise. These are shown to be realatively small, and even in extreme cases unlikely to exceed ±1.0 D for the lesn and + 0.5 D for the eye.