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The stenopaeic slit: an analytical expression to quantify its optical effects in front of an astigmatic eye
Author(s) -
Escrivá L. Muñoz,
Furlan Walter D.
Publication year - 2001
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 - 10.1046/j.1475-1313.2001.00582.x
Subject(s) - slit , astigmatism , optics , refraction , physics , simplicity , residual , expression (computer science) , optical power , front (military) , computer science , algorithm , laser , quantum mechanics , meteorology , programming language
Summary The stenopaeic slit is a trial case accessory used in subjective refraction, especially when high astigmatism is present. In spite of its simplicity, the effect of the slit when it is not oriented along one of the principal meridians of the examined eye is difficult to predict, even in terms of classical geometrical optics. In this paper, the optical principles of the slit are considered with full details in the theoretical framework of the dioptric power space. An analytical expression to obtain the residual refractive error when a stenopaeic slit is placed in front of an astigmatic eye at any orientation is deduced. In the light of these results, some aspects of the clinical procedure are discussed.